A wafer structure for forming a semiconductor single crystal film comprises a semiconductor single crystal substrate, a plurality of recesses formed in a grooved shape to one main surface of the semiconductor single crystal substrate, insulation material embedded to the inside of these recesses, an insulation layer deposited over the insulation material and the semiconductor single crystal substrate and integrated with the insulation material and a polycrystalline or amorphous semiconductor layer to be recrystallized disposed over the insulation layer.A wafer structure with no or less grain boundaries can be obtained. Further, polycrystalline or amorphous semiconductor layer can be prevented from peeling off the substrate by the additional layering of a protecting insulation layer.