Method for manufacturing catalyst from recovered catalyst

The present invention relates to a method for manufacturing a regenerated catalyst from a recovered catalyst from manufacturing process or a used catalyst of a heteropoly acid-based catalyst containing molybdenum, phosphorus, vanadium or copper as an essential component by the below-described Process a to Process f: Process a: a solution A is prepared by mixing a substance M with an aqueous solvent and removing a component insoluble in the solvent; Process b: the molar quantity of at least one component of molybdenum, phosphorus, vanadium or copper contained in the solution A is measured; Process c: an aqueous hydrogen peroxide solution is added to the solution A to obtain a solution B; Process d: the difference between the content obtained in Process b and the theoretical value of a required element is determined and the shortage amount of the catalyst component is added to the solution B to prepare a solution C; Process e: the solution C is dried to prepare catalyst granules D; and Process f: the catalyst granules D are molded and subsequently calcined to prepare a molded catalyst E, the manufacturing method is also simple, and the obtained said regenerated catalyst has performance equivalent to an unused target catalyst, leading to a large advantage that it can be used as it is in combination with an unused target catalyst.