A method for joining members includes: providing a wall surface body which is a die-molded article provided with a hole portion with a draft angle provided from its opposite end portions toward its center portion, a tubular body with a hollow shape, and an elastic body; inserting the tubular body into the hole portion in the wall surface body; inserting the elastic body into the inside of the tubular body; and compressing the elastic body in the direction of an axial line L of the tubular body to expand the elastic body outwardly in the radial direction of the axial line L, thereby deforming and expanding the tubular body to joint the tubular body to the wall surface body by press-fitting.