To suppress variation in processing on a substrate in a substrate processing apparatus for applying the processing to the substrate.
In the substrate processing apparatus 1, a circular cover 61 is provided oppositely to a circular surface 51a of a rotating section 51 rotating while holding a substrate 9, and an air discharge passage 64 communicating to a gap 62 between the cover 61 and the circular surface 51a along the external periphery of the cover section 61 is formed by a duct main body 63 connected to the cover 61 along the external periphery of the cover 61. Since the cross sectional area of the air discharge passage 64 increases gradually along a rotational direction of the rotating section 51, the substrate processing apparatus 1 can reduce variation in an inlet speed of air in the gap 62, and can suppress the variation in processing on the substrate 9.
HIRAE SADAO
SAKAI TAKAMASA
