Toshiba ER-WM01C Microwave Uses Semiconductors to Cut Cold Spots

Toshiba has announced the ER-WM01C, a microwave oven that the company says is the first household model in Japan to use semiconductor oscillation for heating. It is scheduled to go on sale in December 2026, with an open price.

The goal is a familiar kitchen annoyance: frozen rice that is scorching at the edges and still cold in the middle, followed by an extra 30 seconds that overheats the rim.

Two microwave sources instead of one

Conventional microwaves rely on a magnetron, which produces powerful microwaves but at a fixed frequency. That tends to concentrate heat in certain spots. Toshiba's new model combines both approaches: a semiconductor source irradiates food from above, while a magnetron heats from below.

The semiconductor side can change its frequency in fine steps, which Toshiba says helps reduce uneven heating. Sensors also measure the microwaves reflected from the food and its surface temperature, and the oven adjusts heating accordingly.

Faster defrosting in company tests

In Toshiba's comparison test, defrosting 100 g of frozen minced meat took about 1 minute 30 seconds, down from roughly 3 minutes 30 seconds on a conventional model. The older model left clumps of meat after defrosting, while the new one produced meat that could be fully broken apart, according to the company.

The ER-WM01C also has a mode called "Sugoraku Atatame", designed to warm a chilled side dish and frozen rice at the same time. Thermographic images released by Toshiba show a smaller temperature spread when heating refrigerated nikujaga (a meat and potato stew) alongside frozen rice, compared with the previous model.

The ER-WM01C is a single-function microwave focused on reheating and defrosting, with a 21-litre interior. The results come from Toshiba's own tests, so independent verification will show how well the design works in everyday use.