PROCESS FOR PRODUCING OXIDE CATALYST AND PROCESS FOR PRODUCING UNSATURATED NITRILE

A method for producing an oxide catalyst containing Mo, V, Sb, and Nb, the method including:a raw material preparation step includingsub-step (I) of preparing an aqueous mixed liquid (A) containing Mo, V, and Sb,sub-step (II) of adding hydrogen peroxide to the aqueous mixed liquid (A), thereby facilitating oxidation of the aqueous mixed liquid (A) and obtaining an aqueous mixed liquid (A'), andsub-step (III) of mixing the aqueous mixed liquid (A') and a Nb raw material liquid (B), thereby obtaining an aqueous mixed liquid (C);a drying step of drying the aqueous mixed liquid (C), thereby obtaining a dried powder; anda calcination step of calcining the dried powder under an inert gas atmosphere,wherein a time elapsed from addition of the hydrogen peroxide to the aqueous mixed liquid (A) to mixing the Nb raw material liquid (B) therewith is less than 5 minutesandthe aqueous mixed liquid (A') before being subjected to the sub-step (III) has an oxidation-reduction potential of 150 to 350 mV.