HIGH-FREQUENCY HEATING DEVICE

To prevent malfunction of switch due to sliding and abrasion of door key and door hook by opening and closing of door of a microwave oven without grease application. A microwave oven comprises a heating compartment 3, a door 4 having a door key 6 for closing the front opening of the heating compartment 3, a hook spacer 13 manipulated by the door 4, a door hook 9 to be engaged with the door key 6, and switches 10, 11, 12 turned on or off by the door key 6 and hook spacer 13, wherein the door key 6 is made of a resin filled with at least one of acicular crystals of potassium titanate, calcium metasilicate, magnesium pyroborate, barium titanate, and zinc oxide of which Mohs's hardness is lower than that of glass fiber, with the diameter of acicular crystal being 0.1 mu m or more and 50 mu m or less, and the door hook 9 to be engaged with the door key 6 is made of a resin material filled with glass fiber, with the resin surface roughness of the door key 6 being smaller than the resin surface roughness of the door hook 9, thereby not required to apply grease on the sliding parts of the door key 6 and door hook 9.