The present disclosure relates to a cooking appliance having a heater vertically movable in a cooking chamber. The cooking appliance according to the present disclosure comprises: a casing having a cooking chamber formed therein; a door rotatably provided at one portion of the casing and opening and closing the cooking chamber; a moving assembly configured to be movable vertically inside the cooking chamber and provided with a heater, and a shielding means configured to prevent leakage of electromagnetic waves through a gap between the casing and the moving assembly. The cooking appliance has the advantage of preventing electromagnetic waves from leaking out.