Abstract: A drive system for rotary drum type drying apparatus including an axial air-gap induction motor mounted in the substantially central portion of a rear surface member of an outer case containing a rotary drum, a blower mounted on a rotor or a rotor shaft of the motor, and a speed reduction gear unit having an input connected to the rotor shaft and an output connected to the central portion of a rear wall of the rotary drum for rotating the rotary drum by transmitting the torque of the motor thereto while reducing the rotational speed. The structural arrangement that the motor, the blower fan, the speed reduction gear unit and the rotary drum are aligned with one another by the rotor shaft permits the drying apparatus to have an overall compact size while minimizing the number of necessary components parts and enabling the drying apparatus to be used in a long service life.