A cooking oven, wherein an upper blowing port blowing hot air in vertical direction and a lateral blowing port for blowing hot air in horizontal direction are provided in a cooking chamber, the upper blowing port is provided in the ceiling wall of the cooking chamber, the lateral blowing port is provided in one of the right and left inside walls thereof, and a suction port is provided in the bottom inside wall thereof in the form of collected perforations, air in the cooking chamber sucked from the suction port is fed to an upper duct and a lateral duct, heated by an upper heater and a lateral heater, respectively, and blown from the upper blowing port and the lateral blowing port, and the distribution of the perforations of the upper blowing port is made such that the distribution of the perforations at a position where the air blows toward air current from the lateral blowing port to a cooked object is made coarser than that at the other positions so that the air current in horizontal direction cannot be obstructed.