A dipping type film-separating apparatus comprises a flow producing device having a plurality of film cartridges arranged at a predetermined spacing, for producing flows of one direction along the film faces of the film cartridges, and wall members on the two sides of the passages of the one-direction flows formed between the adjoining film cartridges. These film cartridges can be mounted on and demounted from the other direction substantially orthogonal to the one-direction flows and substantially orthogonal to the arranging direction of the film cartridges.