The present disclosure provides a substrate processing apparatus capable of stably controlling a meniscus position. The substrate processing apparatus comprises a head unit configured to discharge a medical fluid; a reservoir configured to store the medical fluid and supply the medical fluid to the head unit; a pressure control unit configured to control pressure in the reservoir; and a trap unit disposed between the reservoir and the pressure control unit and configured to trap a mist generated by the reservoir.

An apparatus for supplying chemical liquid may include at least two ink jet heads, a reservoir for receiving a chemical liquid provided onto a substrate from each of the at least two ink jet heads, a chemical liquid supplying member for providing the chemical liquid to each of the at least two ink jet heads, and a chemical liquid collecting member for drawing and collecting a chemical liquid remaining in each of the at least two ink jet heads. One path of the chemical liquid from the chemical liquid supplying member to the chemical liquid collecting member via one of the at least two ink jet heads may be substantially the same as a length of another path of the chemical liquid from the chemical liquid supplying member to the chemical liquid collecting member via the other of the at least two ink jet heads.