To provide a method for producing an acrylic resin open cell porous body by which time for enabling slurry casting is elongated to facilitate casting of a complex shaped or large sized article without widening the casting port, while making good use of long points inherent in the acrylic resin porous body such as short curing time and high strength, and in which a simple device similar to that for a gypsum molding can be used without direct pressing of the slurry to afford better filling ability than the gypsum molding using only vacuum suction, and to provide the acrylic resin open cell porous body.

This acrylic resin open cell porous body is obtained by mixing and curing a raw material composition comprising an acrylic monomer, an organic filler comprising one or more selected from among a homopolymer, a copolymer and a crosslinked body thereof made from an acrylic monomer and methacrylic monomer as starting materials, a curing accelerator, a polymerization initiator, a surfactant and water for formulation.