The present invention has a configuration of controlling a motor so as to stop a radiation antenna when the radiation antenna faces in a direction in which a reflected wave detection amount is minimized and to stop the radiation antenna when the radiation antenna faces in a different direction different from the direction in which the reflected wave detection amount is minimized. According to this configuration, first, the radiation antenna stops when facing in the direction in which the reflected wave detection amount is minimized. This extends a heating time under the most efficient condition, improving a heating efficiency in comparison with when the radiation antenna constantly rotates. Second, the radiation antenna stops when facing in the different directions. This causes uneven heating when the radiation antenna faces in the direction in which the reflected wave detection amount is minimized as well as when the radiation antenna faces in the different directions. As a result, the uneven heating is cancelled out by the uneven heating each other caused at different locations. In this way, it is possible to achieve the even heating.