Can You Microwave Bento Boxes? (Materials, Should You Do It + More)

Bento boxes are no longer limited to Japan. People all around the world are enjoying the benefits of preparing meals in bento boxes for school, work, and casual events like picnics.

Food inside bento boxes can get cold so you might wonder if you can microwave your bento box. I did the research, and here is what I discovered!

Can You Microwave Bento Boxes?

Whether a bento box is suitable to be microwaved depends on the material and brand of the bento box. As long as the bento box is labeled microwave-safe, you should be able to microwave the bento box worry-free. Typically, it is bento boxes that are made of ceramics, glass, and certain types of plastic that are microwave-safe.

Are you interested to know more about microwaving bento boxes? To learn which types of bento boxes you can microwave and how to microwave bento boxes, keep reading!

Can You Microwave Wooden Bento Boxes?

Wooden bento boxes can be microwaved if there is a microwave-safe label on the underside of the bento boxes or in the packaging.

However, even microwave-safe bento boxes should not be microwaved for a long time. When overexposed to heat, wooden bento boxes can dry out and burn.

Nonetheless, if you plan on microwaving wooden bento boxes, make sure that the bento box is wet and that you do not microwave for more than a few seconds.

Can You Microwave Metal Bento Box?

Metal bento boxes, regardless of whether it is enamel, aluminum, or steel, should never be microwaved. When microwaved, the metal bento box is likely to create dangerous sparks.

Additionally, metal bento boxes cannot absorb heat. As a result, the heat bounces back to the microwave, and the microwave can get damaged in the process.

Can You Microwave Plastic Bento Box?

You should always check the plastic bento box or the manufacturer’s website to see whether the plastic bento box is microwave-safe.

If the plastic bento box is single-use only, it is likely that the bento box is not suitable to be microwaved. However, there are bento boxes made of plastic that are microwave-safe.

Can You Microwave Glass Bento Box?

Glass bento boxes are usually microwave-safe. Generally, these microwave-safe glass bento boxes are made of titanium oxide crystal glass, glass ceramics, or borosilicate glass.

These types of glass are heat-resistant and can be used to microwave food for several minutes on high heat.

To be sure whether your glass bento box is microwavable, look for a microwave-safe label or contact the manufacturer.

Can You Microwave Ceramic Bento Box?

Ceramic bento boxes are known to be microwave-safe. Nevertheless, not all ceramic bento boxes are made equal even if they are all classified as heat-resistant.

Some ceramic bento boxes can be microwaved for several minutes while other ceramic bento boxes should only be microwaved for a few seconds

If the ceramic bento box has any metallic decorations, do not microwave the bento box. Small metallic decorations can cause sparks that can damage the microwave and bento box.

Can You Microwave Sistema Bento Box?

Sistema bento boxes can be microwaved. As per the Sistema bento boxes’ manufacturer, you should keep the bento boxes’ lid off in the microwave.

However, Sistema has not confirmed whether it is because the lid is not microwave-safe, or it is simply to ensure the thorough heating of the food inside the bento box.

Are Bento Boxes Microwave-Safe?

Are Bento Boxes Microwave-Safe?

Bento boxes can be made from a wide variety of materials. As such, there is no singular answer as to whether or not bento boxes are microwave-safe.

If you intend to microwave your bento boxes, you should buy bento boxes made from ceramics, glass, and plastic.

Additionally, just because a bento box is microwave-safe does not mean you can microwave the bento box for a long time. Always make sure you follow the manufacturer’s instructions.

Are Umami Bento Boxes Microwavable?

While Umami bento boxes are microwave-safe, Umami bento boxes have limitations that you must strictly follow.

According to the manufacturer, Umami bento boxes must only be microwaved for a maximum of three minutes. Any longer than three minutes can damage the bento box.

Moreover, you should never use Umami bento boxes to cook food since Umami bento boxes are only good for reheating.

Are Hakoya Bento Boxes Microwave-Safe?

To know whether a Hakoya bento box is microwave-safe, refer to the manufacturer’s website or the bento boxes’ packaging.

Typically, Hakoya bento boxes are microwave-safe except for the inner lid. If you microwave a Hakoya bento box with the inner lead, the Hakoya bento box might not close anymore.

Are Bento Cubes Microwave-Safe?

Bento Cubes by Sistema are microwave-safe when lidless. Other than the lid, Sistem has not indicated other parts of the Bento Cubes that should not be placed in the microwave.

Can You Put A Metal Lunchbox In The Microwave?

Metal lunchboxes are not microwave-safe. If you microwave a metal lunchbox, the lunchbox will reflect the microwave’s heat and cause sparks.

Moreover, the microwave can get damaged and malfunction. While some metal lunchboxes can be microwaved without obvious repercussions, you should not take the risk.

How Do I Know If My Lunch Box Is Microwavable?

Lunchboxes like bento boxes will usually have a microwave-safe label either at the bottom of the box or on the packaging. If there is none, contact the manufacturer.

If you cannot confirm whether the bento box is microwave-safe, do not use the bento box in the microwave.

Are You Supposed To Microwave Bento?

Bento is generally enjoyed cold or at food temperature. As such, most bento boxes are not designed to be microwave-safe.

In case you want your bento hot, make sure to use a microwave-safe bento box or simply transfer the bento to a microwave-safe dish.

Take a look at our other articles to find out if you can microwave Brussel sprouts, if you can microwave bagels, and f you can microwave beets.


Bento boxes come in all shapes, designs, and materials, some of which are microwave-safe, and others not.

Typically, bento boxes are not microwave-safe because bento should be eaten warm or cold. However, there are several manufacturers today who produce microwave-safe bento boxes.

Before microwaving, you should always check the manufacturer’s instructions to preserve the integrity of your bento box.

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