To provide a spin processing apparatus capable of effectually and securely drying processing for upper and lower surfaces of a substrate.

There are provided a cup body 21 where its upper surface is opened and an exhaust hole 39 is formed in a bottom peripheral portion, a driving shaft 26 inserted from the cup body into the same and rotated by the driving source 25, a rotary table 27 provided on the driving shaft for holding a substrate 20 and rotated with the driving shaft, and a cover 51 having an introduction hole 52 provided over the upper surface opening of the cup for producing a gas flow along a peripheral portion of an upper surface central portion of the substrate by allowing the rotary table to be rotated and having an opening portion 53 for causing a gas flow directed from an upper surface side of the cup 21 to the exhaust hole.