This particulate matter reducing apparatus 10 is provided to burn and reduce particulate matter (“PM”) in an exhaust gas 1 of a diesel engine while collecting the PM on each filter 11 at a low collection rate of 50% or less in total. The filter 11 is composed of a wire mesh structure and is formed in a short column shape provided with a central through hole 12. The filter 11 is coaxially housed in an outer cylindrical casing 4 with a gap 14 provided within the casing and is retained by a pair of front and rear shielding plates 17 and 18. The pair of shielding plates 17 and 18 divides the inside of the outer cylindrical casing 4 in front and rear and is provided with one or more air holes 15 and 16 at the outer circumferential section or at the central section.