PURPOSE: To reduce the consumption of a coating agent and to realize the cost reduction of a product, in a spin coater for forming a coating film on a substrate by providing a solvent ejecting means for applying a solvent to the substrate.

CONSTITUTION: In a spin coater having a nozzle 8 for applying a photoresist to a substrate and forming a photoresist film by rotating the substrate 1, a nozzle 10 for discharging a solvent to the substrate 1 is provided. Therefore, when the photoresist film is formed, the solvent is discharged along with the photoresist. Since the photoresist increases in viscosity with the elapse of time, even when centrifugal force due to rotation is utilized, the photoresist gradually becomes hard to spread over the substrate 1 but the rise of viscosity can be prevented by the solvent discharged along with the photoresist and the sliding of the resist on the substrate 1 can be enhanced.