Patent ID: 7918242

Claim:
A processing solution supply system comprising: a processing solution tank containing a processing solution; a pressurizing means for pressurizing the processing solution contained in the processing solution tank to supply the processing solution by pressure; a temporary storage tank for temporarily storing the processing solution supplied by pressure from the processing solution tank, connected to the processing solution tank by a first processing solution supply line; and a second processing solution supply line connecting the temporary storage tank to a processing solution discharge nozzle; the improvement comprising: a pressure sensing means placed in the first processing solution supply line to measure pressure exerted on the processing solution contained in the processing solution tank; a first shut-off valve placed in the first processing solution supply line; a variable pressure regulating means placed in a main pressurizing line connecting the pressurizing means to the processing solution tank; a pressurizing shut-off valve placed in an auxiliary pressurizing line connecting the temporary storage tank to the pressurizing means; a control means that controls the pressure regulating means on the basis of a pressure signal indicating a pressure measured by the pressure sensing means and provided by the pressure sensing means to regulate pressure on a discharge side of the pressure regulating means so that the processing solution is pressurized at a constant pressure, and switches the pressurizing shut-off valve, and the first shut-off valve placed in the first processing solution supply line when it is decided that the processing solution contained in the processing solution tank has been depleted on the basis of a pressure difference between a desired pressure and a measured pressure measured by the pressure sensing means, wherein the auxiliary pressurizing line is connected to the pressurizing means, and a drain line is connected to an upper part of the temporary storage tank.