Metal oxide semiconductor field effect transistors (MOSFETs) using SiC on insulator (SiC-OI) substrate with the structure of 3C-SiC (100)/SiO2/Si have been fabricated. SiC-OI substrates with SiC thicknesses of 100 nm and 600 nm are employed as starting materials and aluminum ions are implanted for p-regions or channel regions with a multi-implantation technique. Afterward, to form the source and drain regions, phosphorus ions are implanted. The gate oxide layer is grown in dry thermal oxidation, followed by post-oxidation annealing. Nickel is used as a contact material for the source and drain region, and aluminum is used for the gate material. From Id-Vd characteristics, 600 nm SiC-OI MOSFET is superior to 100 nm SiC-OI MOSFET. It is might that the crystalline quality of surface SiC layers affects the performance of MOSFET. SiC-OI MOSFET is operated successfully for the first time.