Ge has been received much interest as a CMOS channel material and a near-infrared optical material due to its superior characteristics. Ge-on-Insulator (GOI) structure is necessary to suppress large leakage current originating from the narrow bandgap for application use. A method combined wafer bonding and layer splitting by hydrogen ion (H+) implantation, known as Smart-CutTM realized for Si-on-Insulator fabrication, has been tried to apply for fabricating GOI with large diameter, uniform thickness, and single crystal. In this study, we fabricated GOI by Smart-CutTM technique and demonstrated electronic and optoelectronic devices on the GOI. Besides, we combined a Ge epitaxial growth method with the Smart-CutTM technique to improve GOI quality.