PURPOSE: To form a GaAs crystal whose surface is a (011) plane, a (111) A plane, a (111) B plane or a (311) A plane by using a simple manufacturing method.

CONSTITUTION: At a GaAs crystal whose surface is, e.g. a (011) plane, one part of an amorphous film 2 formed on a GaAs layer 1 whose surface is a (100) plane is removed along the longitudinal direction extended to the [0-1-1] direction of the GaAs layer 1, and one part of the GaAs layer 1 is exposed. Then, the crystal is heated at a temperature of 550 to 600°C; the gas of an alkylate or a hydride of arsenic and the gas of an alkylate of gallium are supplied at a flow rate not exceeding 1SCCM; a GaAs crystal 4 whose one face is a (011) plane is formed on said exposed GaAs layer 1 at a growth speed of 0.87μm/h by using the growth method of a semiconductor crystal.