A cooking appliance including a heater that is vertically movable in a cooking chamber is proposed. The cooking appliance includes a casing having a cooking chamber therein, a door rotatably provided at one portion of the casing and opening and closing the cooking chamber, a heater provided at one portion of the casing and generating heat, a movable heater system provided at one portion of the casing and allowing the heater to be movable in the cooking chamber, and a detection function detecting whether or not the heater is brought into contact with food in the cooking chamber or is spaced apart from the food at a predetermined distance and a function of detecting recovery of the heater to the original position. With the cooking appliance, there is an advantage in that cooking efficiency is improved and malfunction or damage to parts is prevented.