To provide a manual device for inserting a lens in the eye with which a surgeon can decide a timing and quantity of rotary motion by him-/her-self without obstructing secure guiding and stable holding of the device.

This manual injector for inserting the lens into the eye has a grip body (1) with a lens accept part (13) for accepting the lens and a piston (2) movably placed in the grip body (1) for inserting the lens guided into the eye. Operating members (5, 6) for moving the piston (2) against the grip body (1) are placed in the piston (2) and is rotatable against the piston (2). Accordingly, the injector is rotatable at an arbitrary angle without requiring substantially changing a position of a hand pushing the piston (2), especially a position of the thumb.