To provide a composite material useful in producing a ceramic filter or the like, its production method, and a ceramic porous body obtained by using the composite material.

A flexible slab foam produced by a normal method is cut into a sheet foam having a specified dimension and subjected to an explosion treatment to remove the cell membranes, and a binder is prepared by compounding an ethylene-vinyl acetate copolymer emulsion with thermally expansible microcapsules. The sheet foam is immersed in the binder at normal temperature for 1 min, taken out, and pressed with a calendar roll to press out a part of the binder. The sheet foam is then dried at 50°C for 5 min to remove a part of water and heated at 140°C, the thermal expansion temperature of the microcapsules, for 1 min to thermally expand the microcapsules to form hollow particles 1. Thus, the hollow particles 1 are bonded to each other and so are part of the hollow particles 1 to the foam backbone, giving the objective composite material.