Abstract: A wafer surface treatment apparatus and method used in the apparatus including a treatment tank with a cylindrical inside with a bottom, a circular recess formed in the bottom of the tank, a plurality of lower fluid holes opened in the recess, and a horizontally long opening provided at lower part of the side wall of the tank. A movable wall is tightly but slidably installed in the cylindrical inside of the tank so that the movable wall forms a closed room with the recess when it comes into contact with the bottom of the tank. Also, a plurality of upper fluid holes are provided so as to communicate with the closed room, and a rinsing water and washing liquid supply/discharge device is connected to the upper and lower fluid holes.