The present invention provides to an exhaust gas purification that has: a base 11 of wall flow structure having inlet side cells 12 in which an end 13 on the exhaust gas inflow side is open and outlet side cells 14 in which an end 15 on the exhaust gas outflow side is open, and a porous partition wall that partitions the inlet side cell and the outlet side cell; and a first catalyst layer 20 and a second catalyst layer 30 disposed in the interior of the porous partition wall 16 so as to be in contact with the inlet side cells 12 and the outlet side cells 14, wherein either one of the first catalyst layer 20 and the second catalyst layer 30 contains an oxidation catalyst but does not contain a reduction catalyst, and the other one contains the reduction catalyst but does not contain the oxidation catalyst; and a ratio of the lengths of the first catalyst layer 20 and the second catalyst layer 30 differs between a surface of the porous partition wall 16 on the side in contact with the inlet side cells 12 and a surface on the side in contact with the outlet side cells 14.