Real-image finder

A real-image finder includes an objective optical system which forms an image of an object onto a primary image forming surface; an ocular optical system through which the object image formed on the primary image forming surface can be viewed; and an image erecting optical system which inverts the object image formed by the objective optical system, in the vertical and horizontal directions. The real-image finder includes: a rectangular body which includes a main frame having a generally U-shape section which is uniform in the optical axis direction, the main frame being provided with a pair of front and rear end openings in the optical axis direction and a side opening, and a separate cover which is adapted to close the side opening of the main frame; a field frame that is supported within the rectangular body on the primary image forming surface; a pair of transparent members which close the pair of front and rear end openings of the rectangular body; at least one sealing member for sealing a contact portion between the main frame and the cover, and for sealing a gap between the rectangular body and the transparent members.