The present invention provides a method for manufacturing a semiconductor substrate in which a semiconductor wafer, formed of a material less likely to increase the hole diameter, is processed to a semiconductor substrate actually applicable to an existing manufacture line. An SiC wafer 12 is temporarily fixed to a Si wafer 18 through a wax 20. The SiC wafer 12 temporarily fixed to the Si wafer 18 is overlapped with a Si wafer 14 having the same hole diameter as the Si wafer 18 through an SOG film 16P. Orientation flats 14A and 18A are aligned, and while the Si wafers 14 and 18 are overlapped with each other, heating is performed under pressure to solidify the SOG film 16P, whereby an SOG solidified film 16S is formed. With the aid of the SOG solidified film 16S, the SiC wafer 12 is adhered to the Si wafer 14. The SiC wafer 12 is adhered at a predetermined position of the Si wafer 14 facing the SiC wafer 12 so as to be transferred from the Si wafer 18 to the Si wafer 14. The unneeded Si wafer 18 is detached, and the wax 20 is then removed.