An edge exposure apparatus performing an exposure process on an edge portion of a wafer having a coating film (resist film) formed thereon includes position detection means for detecting positional data of an outer edge of a wafer held by a spin chuck, an exposure portion for performing an exposure process on the edge portion of the wafer, a development nozzle supplying a developer to the exposed region, and alignment means for horizontally moving the spin chuck. An exposure process is performed by the exposure portion on the edge portion of the wafer held by the spin chuck while the alignment means is controlled, based on the positional data of the outer edge of the wafer which is detected by the position detection means, such that the positional relation between the outer edge of the wafer and the exposure portion is kept constant.