To provide an ophthalmic device which is resistant to chattering of a slide, and allows easy readjustment even in the chattering.

The ophthalmic device has a straight guiding rail mechanism which comprises a fixed rail for driving a moving table forward the first direction relative to a base table and a movable rail for putting a rotator on the fixed rail to face, wherein the base table and the fixed rail are fixable with a screw, one of the base table and the fixed rail is settled with a tap screw, another of them is furnished with an inclined plane in the direction of the movable rail in their contact surface, and the end of the tap screw is pushed against the inclined plane by a pressure adjusting mechanism for adjusting gap and pressure.