There are here disclosed a method for removing a titanium-based film from a honeycomb-molding die having on the surface of a base material coated with the titanium-based film, and a method for removing an oxide of titanium from a honeycomb-molding die having the oxide of titanium adhered/deposited on the surface of a base material. In each method, a removing solution comprising a mixture of an acid and hydrogen peroxide is used. According to the methods for removing the titanium-based film and the oxide of titanium, a large amount of the titanium-based film as well as the oxide of titanium adhered/deposited on the base material of a honeycomb-molding die can be removed by use of a small amount of the removing solution without corroding the base material of honeycomb-molding die while re-deposition of dissolved titanium ions on the base material is prevented.