PURPOSE: To cool respective parts of an oven and a grill and simultaneously supply combustion air thereto to improve combustion and cooling performances by exhausting cooling air which has cooled electric parts of a high-frequency heating unit through an opening on the front surface of the main apparatus body and simultaneously cooling the oven and grill.

CONSTITUTION: Cool air drawn in through a suction port 6 by means of a cooling fan 7 cools electric parts of a high-frequency generator 8, a high-frequency transformer 9 and the like. then, the cool air reaches a branching plate 19 via a space between a first guide 15 and a rear wall plate 19 and a space between a second guide 16 and a partitioning plate 13, and is divided into two directions at this position. A part of the branched cool air passes through a perforation 18 by means of the branching plate 19 to cool respective parts of the oven 1 and the grill 2 and is exhausted to the exhaust port 4 or supplied to the oven 1. The remaining part of the cool air proceeds straight and is exhausted through an opening 17.