Abstract: An apparatus for washing a substrate comprises a spin chuck for holding and rotating a substrate, washing brush mechanism for supplying a washing liquid onto a surface of the substrate held on the spin chuck, and applying a physical force to contaminants present on a surface of the substrate so as to remove contaminants, a supporting arm for supporting the washing brush mechanism, an arm driving mechanism for driving the supporting arm to move the washing means along the surface from a central portion toward a peripheral portion of the substrate, and a control device for controlling the operation of at least one of the washing means, the spin chuck and the arm driving mechanism so as to control the physical force acting on the contaminants present on the surface of the substrate depending on the state of the contaminants.