PURPOSE: To form an InP layer in excellent crystallizability on an Si crystal in the concrete in relation to the phase of the semiconductor thin film growing method.

CONSTITUTION: Within the epitaxial growing method of an InP crystal 4 on an Si substrate 1, a compound semiconductor layer comprising an Inks layer 3 or GaAs 2 and Inks 3 is formed between the SI crystal 1 and the InP crystal 4. In such a constitution, the kind of the compound semiconductor material as the intermediate layer to be inserted between the Si substrate 1 and the InP crystal 4 is differentiated from that of the intermediate layer used in the conventional method.