Abstract: The Ga2O3-based single crystal substrate has an amount of warpage of ?50 ?m or more and 50 ?m or less (including 0 ?m) on a main surface. The method of manufacturing a Ga2O3-based single crystal substrate includes processing a substrate from a Ga2O3-based single crystal grown according to an induction heating type single crystal growth method to have an amount of warpage of ?50 ?m or more and 50 ?m or less (including 0 ?m) on a main surface.

Abstract: Provided is a gallium oxide single crystal and a gallium oxide single crystal substrate that can improve the luminous efficiency. In a gallium oxide single crystal 13, the dislocation density is less than or equal to 3.5×106/cm2. The gallium oxide single crystal 13 is manufactured by the EFG method. Further, the seed touch temperature in the EFG method is greater than or equal to 1930 degrees centigrade and less than or equal to 1950 degrees centigrade. A neck part 13a of the gallium oxide single crystal 13 is less than or equal to 0.8 mm. A gallium oxide single crystal substrate 21 is made of the gallium oxide single crystal 13.