A storage catalyst 3 is constituted of a supporter substrate 30, which is formed of at least one member being selected from the group consisting of Al2O3, CeO2, ZrO2, TiO2 and zeolite, and whose specific surface area is 30 m2/g or more, and a coating layer 31, which includes a supporting powder including at least one member being selected from the group consisting of Al2O3, CeO2, ZrO2, TiO2 and zeolite, a storage material for storing NOx and SOx, the storage material being supported on the supporting powder, and a noble metal being supported on the supporting powder.Since the supporter substrate 30 has a large specific surface area, a supporting amount of the storage material for storing NOx and SOx augments remarkably. Therefore, an SOx storage amount of the storage catalyst, which is put in place on an upstream side of an NOx storage-and-reduction catalyst, augments, and thereby an NOx storage amount in low-temperature regions augments.