A compound semiconductor single-crystal manufacturing device (1) is furnished with: a laser light source (6) making it possible to sublime a source material by directing a laser beam onto the material; a reaction vessel (2) having a laser entry window (5) through which the laser beam output from the laser light source (6) can be transmitted to introduce the beam into the vessel interior, and that is capable of retaining a starting substrate (3) where sublimed source material is recrystallized; and a heater (7) making it possible to heat the starting substrate (3). The laser beam is shone on, to heat and thereby sublime, the source material within the reaction vessel (2), and compound semiconductor single crystal is grown by recrystallizing the sublimed source material onto the starting substrate (3); afterwards the laser beam is employed to separate the compound semiconductor single crystal from the starting substrate (3).