Disclosed is a sponge roller (1) which comprises: a generally cylindrical roll body (3) which is formed from a porous polyvinyl acetal resin material that is elastic in a wet state; and a plurality of projections (5) which are integrally formed on the outer circumferential surface (3a) of the roll body (3). The sponge roller (1) cleans a surface to be cleaned by bringing the plurality of projections (5) into rotary contact with the surface to be cleaned. The polyvinyl acetal resin constituting the sponge roller (1) has an anionic functional group.
