A substrate processing apparatus may include a first disk provided in a chamber and configured to perform a turning motion and to include a plurality of seating holes periodically arranged within a specific radius from a center axis, a plurality of second disks provided in the seating holes, respectively, and configured to perform a revolving and rotating motion in accordance with the turning motion of the first disk, a first rotary connector structure provided between the second disk and the seating hole to allow for a rotating motion of and for an electric connection to the second disk, an electrostatic chuck provided on the second disk and configured to hold a substrate using an electric power supplied through the first rotary connector structure, and a first magnetic gear fixed to the second disk and configured to exert a torque on the second disk, and a second magnetic gear.