Preparation and properties of a new type a-Si:H solar cell based on an organic polymer film are described. Also are discussed the electrical and the optical properties of GD-CVD a-Si:H film used for the cell. The conversion efficiency of an polyimide/sputtered SUS/p-i-n a-Si:H/ITO cell with a size of 9 mm2 was 6.03% under the illumination of 92.5 mW/cm2 (AM-1). Cells on the polyimide film are stable even in high humidity over 150 days and allow flexible folding without any deterioration of the conversion efficiency. However, the conversion efficiency is always somewhat lower as compared with cells on SUS plate. Examining the correlation between the conversion efficiency and the surface morphology of a-Si:H layers, it was revealed that the higher roughness of sputtered SUS layer on polyimide film reduces the output current of the cell.