The present invention addresses the problem of providing a me thyl methacrylate expanded mold article that rarely generates smoke and soot upon ignition, that can be expanded at a high expansion ra tio, and that is hardly broken upon deformation. The problem is sol ved by an expandable poly methyl methacrylate particle comprising a polymer obtained from 100 parts by weight of an acrylic monomer, a nd not less than 0.05 parts by weight and not more than 0.15 parts b y weight of a polyfunctional monomer, wherein the acrylic monomer c omprises not less than 90% by weight and not more than 98% by weight of methyl methacrylate and not less than 2% by weight and not more than 10% by weight of an C 2-8 alkyl acrylate.