An exhaust gas purification apparatus for lean combustion engines, comprising at least: one or more oxidation catalysts which oxidize at least one selected from the group consisting of CO, HC, NO and NH 3 in an exhaust gas discharged from a lean combustion engine; a reducing agent supplying unit for supplying one or more reducing agents selected from the group consisting of a urea component and an ammonia component into an exhaust gas flow channel; and one or more selective reducing catalysts which adsorb ammonia and bring the ammonia into contact with NO x to perform reduction, wherein the one or more selective reducing catalysts comprise a first catalyst region containing a non-zeolite-based catalyst material containing at least an oxygen storage and release material and a transition metal element, and a second catalyst region containing at least zeolite and a transition metal element supported on the zeolite, wherein the first catalyst region contains at least the oxygen storage and release material and one or more transition metal elements selected from the group consisting of W, Nb and Ti supported on the surface of the oxygen storage and release material, and the second catalyst region contains at least the zeolite and one or more selected from the group consisting of Cu, Fe, Ce, Mn, Ni, Co, Ca, Ag, Rh, Ru, Pd, Pt, Ir and Re and supported on the zeolite, the maximum amount of NH 3 adsorbed per unit volume of the first catalyst region is smaller than the maximum amount of NH 3 adsorbed per unit volume of the second catalyst region under a condition of NH 3 adsorption at 33% of the saturated adsorption amount, and the first catalyst region is arranged on the upstream side of the exhaust gas flow channel for the exhaust gas with respect to the second catalyst region so that the exhaust gas contacts the first catalyst region and the second catalyst region in this order. wherein the one or more selective reducing catalysts comprise a first catalyst region containing a non-zeolite-based catalyst material containing at least an oxygen storage and release material and a transition metal element, and a second catalyst region containing at least zeolite and a transition metal element supported on the zeolite, wherein the first catalyst region contains at least the oxygen storage and release material and one or more transition metal elements selected from the group consisting of W, Nb and Ti supported on the surface of the oxygen storage and release material, and the second catalyst region contains at least the zeolite and one or more selected from the group consisting of Cu, Fe, Ce, Mn, Ni, Co, Ca, Ag, Rh, Ru, Pd, Pt, Ir and Re and supported on the zeolite, the maximum amount of NH 3 adsorbed per unit volume of the first catalyst region is smaller than the maximum amount of NH 3 adsorbed per unit volume of the second catalyst region under a condition of NH 3 adsorption at 33% of the saturated adsorption amount, and the first catalyst region is arranged on the upstream side of the exhaust gas flow channel for the exhaust gas with respect to the second catalyst region so that the exhaust gas contacts the first catalyst region and the second catalyst region in this order.