a catalyst for the selective reduction of nitrous oxide with ammonia contains , in addition to titanium oxide as component , at least one oxide of w , si , b , al , p , zr , ba , y , la , ce and at least one oxide of y , nb , mo , fe , cu as component , whereby the atomic ratio between the elements of components and amounts to 1 : 0 . 001 up to 1 . the catalyst can be obtained by kneading reactive titanium oxide with a high specific surface of predominantly anatase with the substances of component or their preliminary stages , adding processing agents , winding up with a homogeneous kneaded mass , extruding the latter , drying the extrudate and calcining in air at 300 °- 800 ° c .