A chemical liquid supply system that prevents the generation of heat during operation in a pump and allows downsizing the discharge pump for instilling a chemical liquid from a tip nozzle. Compressed air is supplied to an upper space of a resist bottle and the chemical liquid is conferred positive pressure and sent out to a pump chamber of a discharge pump, thereby the pump chamber is filled with a resist liquid. This eliminates the need of a conventional construction where a spring or others are used to drive a flexible membrane of the discharge pump to the operation chamber side to take in the resist liquid. As a result, no electric motor is used, so there is obviously no risk of heat damage to a semiconductor wafer and the discharge pump itself can be further downsized.