A chemical liquid supplying apparatus which can discharge chemical liquid with high accuracy is provided. The apparatus is used to discharge the chemical liquid in a chemical liquid tank from an application nozzle. The apparatus has a combined member formed integrally with a pump case and a cylinder, and a flexible tube serving as a pump member is provided in the pump case, wherein its inside is a pump chamber and its outside is a pump-side driving chamber. A piston is assembled to the cylinder and when the piston is reciprocated by a motor, the pump chamber is expanded and contracted. A gap between the piston and the cylinder is covered with a diaphragm, and an interior of the diaphragm is a seal space. Therefore, an incompressible medium having leaked from the gap between the piston and the cylinder enters into the seal space and does not leak to the outside.