Diesel Particulate Filter (DPF) is one of the promising methods to reduce diesel engine exhaust particulates which cause environmental pollution. Several materials have been studied for DPF for about 15 years. However the ceramic honeycomb type DPF system has problems such as cracking and melting during regeneration and the metal type DPF system is trouble with corrosion and low trapping performance. Currently there are no practical materials for DPF.This paper presents new metal porous matter (Celmet) which have low corrosion in high temperature exhaust gas and high trapping performance, and which is suitable as a DPF. We mainly discuss the relation between the porous metal structure and trapping performance and between the metal component and corrosion in high temperature exhaust gas.