Disclosed is a liquid treatment for an object to be processed, such as a semiconductor wafer or a glass LCD substrate, which is designed to remove any chemicals remaining in chemical supply nozzles and also improve the rinse capability and throughput. To that end, a processing liquid supply means is configured as jet nozzle pipes 40, a bottom surface 40c of each of the jet nozzle pipes 40 is inclined so as to slope downward from a chemical supply side thereof to an end portion, and the end portion is connected to a drain pipe 55 by a waste liquid orifice 40d and a drain valve 54. A chemical is supplied from nozzle orifices 40b of the jet nozzle pipes 40, the chemical is brought into contact with wafers W, and a treatment is performed thereby. Thereafter, a chemical-removing agent such as pure water or N.sub.2 is supplied through the jet nozzle pipes 40 to remove any remaining chemical from the jet nozzle pipes 40, then pure water is brought into contact with the wafers W to wash them.