PURPOSE: To enable an interior of a heating chamber to be kept clean by a method wherein purifying catalyst is arranged at an inner wall surface of the heating chamber of a heating and cooking unit in which an induction heating and a resistive heating can be selectively or simultaneously performed so as to perform continuously a complex cooking combined with a high frequency heating and a heater heating operation.

CONSTITUTION: An inner casing (a heating chamber) 2 is arranged within an outer casing 1 and a purifying catalyst 3 is installed at an inner wall surface of the inner casing 2. The inner casing 2 has a pair of induction heating electrodes 4 and 4' having several small holes, a high frequency transmitting device for impressing a high frequency voltage to the electrodes 4 and 4', and a pair of heaters 5 and 5 ' arranged at the upper and lower portions of the electrodes 4 and 4 '. In case that electrodes 4 and 4 ' are energized through a power supply cord 8 and a high frequency heating process is to be carried out, for example, fishes or the like are defreezed, a cooked item is placed on the electrode 4', the lower electrode 4' is moved upward and the unit is set to have a state in which there in no clearance in respect to the upper electrode 4 and a high frequency current is applied so as to defreeze the cooked item. Subsequently, in case that a baking cooking is to be carried out, the power supply is changed over to heaters 5 and 5' so as to perform a heating operation.