A chemical liquid purification apparatus includes a tank body, a return tube, a liquid sending pump, a filtration device and a piping. The tank body has a liquid passage port and a circulation port communicated to a storage space inside the tank body. The return tube has one end connected to the circulation port and another end extending to the storage space. The liquid sending pump and the filtration device are located outside the tank body in between the liquid passage port and the circulation port. The piping is connecting the liquid sending pump and the filtration device to the liquid passage port and the circulation port.