A catalytic converter for cleaning exhaust gas includes a heat-resistant support, and a coating formed on the support. The coating contains at least one kind of catalytically active substance and at least one kind of oxygen-storing oxide. The oxygen-storing oxide is selected from oxides of Pr and Tb. The oxygen-storing oxide may be Pr.sub.6 O.sub.11 or Tb.sub.4 O.sub.7. Alternatively, the oxygen-storing oxide may be a complex oxide which may be represented by the formula, Ce.sub.1-(x+y) R.sub.x E.sub.y Oxide or Ce.sub.1-(x+y) R.sub.x Zr.sub.y Oxide where "R" represents Pr or Tb, "E" represents an element selected from a group consisting of Nd, Y and Gd.