In a simultaneous coating of multiple layers on a web using a slide hopper type coating apparatus, the gelatin concentration of the coating liquid for the bottom layer is set to be lower than the gelatin concentration of the coating liquid for the middle layer by at least 2 points in percentage, the ratio A/B, which is the flow amount ratio of the coating liquid for the bottom layer with respect to the entire multi-layered coating liquid, is set to be between 0.05 and 0.2, and the ratio C/D, which is the viscosity ratio between the coating liquid for the bottom layer and the coating liquid of the middle layer, is set to be between 0.2 and 0.67. Thereby, the flow of the multi-layered coating liquid flowing down on the slide surface can be stabilized.