The cooker is equipped with a heating chamber (2) that has an open part (2d) in the front surface and that holds the material to be cooked, an opening/closing door (3) that has a see-through window (4) and that opens and closes the open part, a suction intake opening (2a) that is open in one of the side walls that faces the heating chamber (2), an air discharge outlet (2b) that is open in the other side wall of the heating chamber (2), and a circulation duct (20) that has first and second side surface parts (20a, 20b) that are provided outside of the two side walls of the heating chamber (2) and that connect the suction intake opening (2a) provided at the first side surface part (20a) and the air discharge outlet (2b) provided at the second side surface part (20b), and a circulation fan (21) that is provided inside the circulation duct (20); and that draws in gas inside the heating chamber (2) through the suction intake opening (2a) and blows it out through the air discharge outlet (2b).