To inexpensively provide a cooker having a low riskiness of scolding a user in a heating chamber of a high temperature when a time is not considerably elapsed after cooking, by easily preventing a contact of a movable heater with a placing shelf for placing a material to be cooked in the case of inputting or outputting the material, in the cooker for heating to cook by moving the heater from a non-heating position to a heating position.

The cooker 33 comprises a heater circuit mechanism having a movable piece 3 rotatably provided at an opening side of a sidewall of a heating chamber 1 to rotate in the case of inputting or outputting a tray 23 to or from the chamber 1, a first arm 30 connected at one end to the piece 3 to rotate together with the piece 3, a second arm 31 fixed at its one end to a rotary shaft of a movable heater 10, a coupling piece 32 for coupling the other end of the arm 30 to the other end of the arm 31, and a spring 35 for urging the heater 10 toward a deep non-heating position of the chamber 1.