A high-frequency heating apparatus comprises a heating chamber, a high-frequency generator, a waveguide, an antenna, a motor for rotating the antenna, and a stage (6) provided above and near the antenna to partition the heating chamber and made of dielectric. A rotary base on which an object to be heated is mounted is provided on the stage. A first magnet is provided to the antenna. A second magnet is provided on the rotary base at a place corresponding to the first magnet on the rotary base. By utilizing the magnetic coupling between the first and second magnets, the rotary base is rotated in synchronism with the rotation of the antenna. While maintaining the advantages of conventional antenna high-frequency heating apparatuses, the heating efficiency by grill heating or oven heating is enhanced, and minute heating uniformness is achieved.