A key frame capable of being easily fitted into a product and that can be prevented from deforming in the fitting. Elastic projections (41p) elastically projecting outward are provided at the lower side and both lateral sides of a hard base (41). The elastic projections (41p) function as fixing members when a cover member for a push button switch is fitted into a housing of the product. Inside an elastic projection (41p) is provided a space (S). When the elastic projection (41p) is pressed from the outside, the space (S) enables the inwardly deformed elastic projection (41p) to enter into the space (S). As a result, the elastic projections (41p) projecting from an outer peripheral line of the hard base (41) can be elastically deformed so as to retract inside the hard base (41).