To contrive the way to efficiently and rationally remove a filter cake from a used filter and reuse it by applying a binder resin soluble in an organic solvent to a base material for a filter and melting the binder resin with the organic solvent to be removed after using the filter, and at the same time, enabling a filtrate to be separable from the filter base material.

A coating liquid obtained by melting, for example, a binder resin consisting of a thermoplastic block copolymer of styrene-ethylene-butylene- styrene (SEBS) in xylol, is applied to a filter base material 2 using a fibrous material 1 of synthetic fiber such as polypropylene. After use for a specified period of time, a filter 3 using this sheet is soaked in xylole to clean a filter cake with the SEBS copolymer. Again the SEBS copolymer is added to the filter, so that it can be reused.