CENTERING DEVICE AND SUBSTRATE PROCESSING APPARATUS

A centering device has three or more contact members each having a contact surface capable of contacting an end face of a substrate supported by a substrate support. These contact members are arranged to surround the substrate support in a horizontal plane with the contact surfaces facing an end face of the substrate. These contact members move toward the substrate in the mutually different directions to sandwich the substrate. Each contact surface is finished such that a contactable region formed to intersect the horizontal plane has a linear shape or a curved shape having a center of curvature located on the substrate side and having the radius of curvature larger than the radius of the substrate and is longer than an arc formed by cutting out the circumference of the substrate by the cut.