A processing-liquid supply apparatus includes a source, a discharge device, a supply channel connecting the source and discharge device, a filter device positioned in the channel to form first side having the source and second side having the discharge device, a pump device positioned in the channel, and a control device which controls suction and discharge by the pump device. The control device controls the pump device such that the liquid is discharged from the discharge device, that remaining of the liquid on the second side is suctioned to be returned to the first side and that the remaining of the liquid returned to the first side flows from the first toward second side together with refill of the liquid from the source, and the control device is set such that return amount of the liquid to the filter device is equal to or greater than amount of the discharge.