Scroll compressor features high efficiency and low vibration, and is adopted in wide variety of refrigerating and air-conditioning products. For the purpose of meeting the demand for further efficiency improvement and large capacity, MHI developed the three-dimensional scroll compressors (3D scroll) for commercial air-conditioner "GU series". By realizing three-dimensional compression which is impossible for the conventional scroll, 5.5% improvement of efficiency, 35% smaller size and 26% lighter weight compared with the conventional compressor were archived, so that substantial energy-saving effect and improvement of unit-mounting capacity are obtained.