A particulate matter oxidizing catalyst includes: at least one metal
selected from the group consisting of: gallium, manganese, iron, cobalt,
nickel, copper, yttrium, zirconium, niobium, molybdenum, silver,
lanthanum, praseodymium, neodymium and gold; and cerium, wherein a first
oxide includes: the cerium, and a first metal which is at least one
element selected from the group consisting of: gallium, manganese, iron,
cobalt and nickel, wherein a second oxide includes: the cerium, and a
second metal which is at least one element selected from the group
consisting of: praseodymium, zirconium and aluminum, and wherein the
second oxide and the first oxide have a content ratio of second
oxide/(first oxide+second oxide)=0.1 by mass to 0.8 by mass.