A work holder (12) for holding a workpiece (2) while partially masking the same by use of a mask (18). The workpiece and the mask are elastically pressed against each other by an aggregate (15) of heat-resistant fiber such as metal fiber or ceramic fiber, so that the workpiece and the mask are brought into close contact with each other. This work holder is adapted to form a resistor film (9) on a part of the surface of a chip (2) to form a chip-type resistor (1), for example, by a thin film forming method such as sputtering.