To provide an operation board with a waterproof operation panel in a small installing space.

The operation board 33 mounting a circuit pattern or circuit parts for operation or/and display only on one surface serving as an electrical mounting surface 33a without using the other surface 33b is arranged so that the surface 33a faces the operation panel 32, and the side of the surface 33a is fitted to the electric pot so as to be partitioned from the inner area 46 of the electric pot by this board 33.