A fluid supply device includes a condenser, a tank that stores the fluid, a pump that pressure-feeds the fluid toward a processing chamber, a main pipe connecting the tank and the pump and transferring the liquid stored in the tank to the pump using a weight of the liquid, and a discharging pipe that is connected to the main pipe at a lowest position of the main pipe at one end, is opened to the atmosphere at the other end, and vaporizes and discharges the liquid in the tank and the main pipe to the outside. The discharging pipe is formed so that, after the liquid in the tank and the main pipe is fully discharged, a liquid pool that separates a space on the atmosphere side and a space on the main pipe side of the discharging pipe is temporarily produced in the discharging pipe.