To improve safety by preventing inadvertent turning on of a tumbler type switch.

An engaging body 11 which suppresses the movement of a operation button 10a from an off to on side is freely slidably supported at a main body of the tumbler type switch 10 while the control button exists at a prescribed position. The objective cooker is so constituted that the on operation of the tumbler type switch 10 by the operation button 10a alone is not possible and that the on operation of the tumbler type switch 10 by the operation of the operation button 10a is possible only after the engaging body 11 is moved form the prescribed position described above to another position and therefore the safety may be assured without running even if a user inadvertently touches the operation button 10a in cleaning, etc.