A method for producing a compound single crystal includes a process (I) of growing the compound single crystal while causing an anti-phase boundary and a stacking fault to equivalently occur in a direction parallel to the surface, the stacking fault being attributable to the elements A and B; a process (II) of merging and annihilating the stacking fault, attributable to the element A, and the anti-phase boundary, which occurs in the process (I); a process (III) of vanishing the stacking fault attributable to the element B, which occurs in the process (I); and a process (IV) of completely merging and annihilating the anti-phase boundary. The process (IV) is carried out simultaneously with the processes (II) and (III) or after the processes (II) and (III).