The present disclosure provides an exhaust gas purification apparatus for motor vehicles that has succeeded in suppressing peeling of a coat layer from an exhaust gas purification catalyst. Such exhaust gas purification apparatus for motor vehicles comprises: an exhaust gas purification catalyst comprising a substrate and a coat layer coated on the substrate comprising a microwave-absorbing material, a noble metal, and aluminum oxide (Al2O3); and a microwave-generating apparatus for heating the microwave-absorbing material located ahead of the exhaust gas purification catalyst with respect to an exhaust gas flow direction, wherein the microwave-absorbing material includes NiFe2O4, the noble metal includes at least one metal selected from the group consisting of platinum (Pt), palladium (Pd), and rhodium (Rh), and contents of zinc oxide (ZnO) and copper(II) oxide (CuO) in the coat layer are equivalent to or lower than the given levels.