The present invention is to provide a catalyst for removing nitrogen oxides which is capable of keeping sufficient denitrification performance, i.e., a high removal rate of nitrogen oxides in exhaust gas having a high NO2 content especially under conditions where the ratio of NO2/NO in exhaust gas is 1 or higher, a catalyst molded product therefor, and an exhaust gas treating method. The catalyst is designed for removing nitrogen oxides, which is used to denitrify exhaust gas containing nitrogen oxides having a high NO2 content, which comprises: at least one kind of oxide selected from the group consisting of copper oxides, chromium oxides, and iron oxides as a component for reducing NO2 to NO; and which further comprises: at least one kind of titanium oxide; at least one kind of tungsten oxide; and at least one kind of vanadium oxide as components for reducing NO to N2.