The present invention is directed to a method for producing a bonded wafer, the method in which heat treatment for flattening the surface of a thin film is performed on a bonded wafer made by the ion implantation delamination method in an atmosphere containing hydrogen or hydrogen chloride, wherein the surface of a susceptor on which the bonded wafer is to be placed, the susceptor used at the time of flattening heat treatment, is coated with a silicon film in advance. As a result, a method for producing a bonded wafer is provided, the method by which a bonded wafer having a thin film with good film thickness uniformity can be obtained even when heat treatment for flattening the surface of a thin film of a bonded wafer after delamination is performed in the ion implantation delamination method.