Abstract: A method of forming a coating film includes rotating a support member to rotate a target substrate in a horizontal state, and supplying a coating liquid onto a target surface from a supply port of a nozzle, while moving the nozzle in a horizontal direction relative to the target substrate being rotated. This method also includes detecting a height of the target surface, and controlling a vertical position of the nozzle, based on a detected height of the target surface, to satisfy a formula, (S/R)>D>0, when supplying the coating liquid. In the formula, S denotes an area of the supply port, R denotes an inner perimeter of the supply port, and D denotes a distance between the supply port and the target surface.