The invention provides an SiC semiconductor element having fewer interface defects at the interface between the SiC and the insulating film of the SiC semiconductor, as well as improved channel mobility. The semiconductor element is provided with at least an SiC semiconductor substrate and an insulating film in contact with the substrate, wherein the insulating film is formed on a specific crystal plane of the SiC semiconductor substrate, the specific crystal plane being a plane having an off-angle of 10-20° relative to the {11-20} plane toward the [000-1] direction or at an off-angle of 70-80° relative to the (000-1) plane toward the direction. Through the use of a specific crystal plane unknown in the prior art, interface defects between the SiC semiconductor substrate and the insulating film can be reduced, and channel mobility of the semiconductor element can be improved.