To provide a pressure plate device which makes the engagement part of a pressure plate and a pressure spring hard, to disengage and is simple in structure and easy to assemble.

This film pressure plate device is a device which is pressed against a film on an aperture part to keep its plane and composed of the pressure plate 11 and the pressure spring 12, which applies an energizing force by the elastic deformation to the pressure plate 11. The pressure plate 11 has an L-shaped press parts 11b and 11c in the four corners on its fitting surface 11e, and the pressure spring 12 is provided with an arm part 12a having two tongue parts 12i and an arm part 12b with two counterposing claw parts 12n. The tongue parts 12i on the side of the arm 12a are inserted into below the press parts 11b, and the counterposed claw parts 12n on the side of the arm part 12b are engaged with the press parts 11c, after elastic deformation state to fit the pressure spring 12 to the pressure plate 11.