A solar cell including a semiconductor substrate having a first conductivity type an emitter region, having a second conductivity type opposite to the first conductivity type, on a first main surface of the semiconductor substrate an emitter electrode which is in contact with the emitter region a base region having the first conductivity type a base electrode which is in contact with the base region and an insulator film for preventing an electrical short-circuit between the emitter region and the base region, wherein the insulator film is made of a polyimide, and the insulator film has a C6H11O2 detection count number of 100 or less when the insulator film is irradiated with Bi5++ ions with an acceleration voltage of 30 kV and an ion current of 0.2 pA by a TOF-SIMS method. The solar cell can have excellent weather resistance and high photoelectric conversion characteristics.