Disclosed is a substrate processing apparatus including a disc provided so as to be rotatable on its axis, at least one susceptor disposed on the disc such that a substrate is seated on an upper surface thereof, the susceptor being configured to rotate on its axis and to revolve around a center of the disc as the disc rotates on its axis, a metal ring coupled to a lower portion of the susceptor, the metal ring being arranged such that a center thereof coincides with a center of the susceptor, and a magnet provided below the disc so as to be radially arranged on a basis of the center of the disc, at least a portion of the magnet being opposite the metal ring in a vertical direction.