A manufacturing method includes depositing a chamber protective layer in a chamber, supplying a first purge gas to the chamber, transferring a substrate to the chamber, the substrate being disposed inside an edge ring on an electrostatic chuck, processing the substrate, supplying a second purge gas to the chamber, transferring the substrate to an outside of the chamber, removing the chamber protective layer, and supplying a third purge gas to the chamber. Variation of the surface roughness of the edge ring may be minimal. A ratio of an edge gas flow rate of gas supplied to an edge of the substrate and the edge ring to a central gas flow rate of gas supplied to a central portion of the substrate in the processing the substrate may be 0.05 to 19. The flow rate ratio may be more than 1 in the supplying the second purge gas.