The present invention relates to an oven (1) which is of the type wherein cooking is performed by microwaves and which comprises a casing (2), a rear wall (3) covering the rear face of the casing (2), a cooking chamber (4) disposed in the casing (2), wherein foods to be cooked are placed, at least one movable element (5) disposed in the casing (2), at least one motor (6) providing the drive of the movable element (5), at least one shaft (7) providing the drive provided by the motor (6) to be transmitted to the movable element (5), a separator (8) separating the volume wherein the movable element (5) and the motor (6) are disposed, having a hole (9) through which the shaft (7) passes, a supporting wall (10) having an opening (11) through which the shaft passes (7), supporting the motor (6) and on which the motor (6) is fixed such as to remain between the rear wall (3) and the supporting wall (10).