The invention provides a method for positioning a wafer and a semiconductor manufacturing apparatus, which are applied to thin film processes. The method includes: Step S1: Obtain the state distribution of the first surface of the first wafer after the thin film process is performed on the first wafer, wherein the first surface is the surface opposite to a surface that the thin film formed thereon in the thin film process; Step S2: Determine whether the first wafer is located at the ideal positioning center according to the state distribution of the first surface, when the first wafer is not located at the ideal positioning center, according to the state distribution of the first surface adjusts the positioning position of the second wafer to be subjected to the thin film process, so that the second wafer is positioned at the ideal positioning center during the thin film process. According to the present invention, the wafer is positioned at the ideal positioning center during the thin film process, thereby improving the quality of the thin film layer and the entire wafer (epitaxial wafer) after the thin film process, and improving the effect of the thin film process.