A semiconductor substrate is manufactured in which a plurality of single crystal semiconductor layers is fixed to a base substrate having low heat resistance such as a glass substrate with a buffer layer interposed therebetween. A plurality of single crystal semiconductor substrates is prepared, each of which includes a buffer layer and a damaged region which is formed by adding hydrogen ions to each semiconductor substrate and contains a large amount of hydrogen. One or more of these single crystal semiconductor substrates is fixed to a base substrate and irradiated with an electromagnetic wave having a frequency of 300 MHz to 300 GHz, thereby being divided along the damaged region. Fixture of single crystal semiconductor substrates and electromagnetic wave irradiation are repeated to manufacture a semiconductor substrate where a required number of single crystal semiconductor substrates are fixed onto the base substrate.