A filter is configured for efficient combustion of particulates accumulated on a catalyst layer 7 in both a rapid combustion range and a slow combustion range. The catalyst layer 7 on an exhaust gas passage wall of a filter 1 includes a mixture of a Rh-doped Ce-containing composite oxide particle material loaded with Pt and a composite particle material loaded with Pt. In mixed particles of this mixture, Zr-containing composite oxide particles containing no Ce and activated alumina particles are mixed together and agglomerated.