PURPOSE: To improve the cleaning property and the thermal efficiency of a heating cooker.

CONSTITUTION: The opening 4 of a cylindrical vacuum double container 1 is blocked by a lid 16 allowable to mount and demount, means 21 and 23 to detect the blocking condition are provided, an opening 19 is provided to the lid 16, the opening 19 is blocked by a door 44 allowable to open and close, a hollow structure is provided to the part of the lid 16 other than the opening 19, and electric heater 34 and 35, or a high-frequency wave source 31, and their controller 51 are provided. As a result, since an electric part and the like are not installed to a container 1 perfectly, and the container 1 can be detected when it is removed from the lid 16, it can be washed as it is, by removing from the lid. And since it is a vacuum double container, an adiabatic characteristic same as a thermos bottle is obtained, and the thermal efficiency is improved.