According to the present invention, there is provided a method for manufacturing an SOI wafer, the method configured to grow an epitaxial layer on an SOI layer of the SOI wafer having the SOI layer on a BOX layer to increase a thickness of the SOI layer, wherein epitaxial growth is carried out by using an SOI wafer whose infrared reflectance in an infrared wavelength range of 800 to 1300 nm falls within the range of 20% to 40% as the SOI wafer on which the epitaxial layer is grown. As a result, a high-quality SOI wafer with less slip dislocation and others can be provided with excellent productivity at a low cost as the SOI wafer including the SOI layer having a thickness increased by growing the epitaxial layer, and a manufacturing method thereof can be also provide.