A masking fixture according to an embodiment of the present disclosure includes an insertion portion fitted into an opening of a workpiece, a covering portion above the insertion portion covering the opening of the workpiece, and an eave portion above the covering portion projecting outwards from an outer edge of the covering portion. In the masking fixture, the eave portion may be arranged higher than the top surface of the workpiece when the insertion portion is fitted into the opening of the workpiece, and a protruding portion may be arranged at the top of the eave portion. The masking fixture may be made of resin.