A pen having an anti-rotation bent tip is provided to be freely used regardless of the angle by restraining the tip from being rotated although a user applies great power to the pen. A pen having an anti-rotation bent tip(1) is composed of: the tip having a bent portion(1a) bent at the predetermined angle in one direction and an anti-rotation projection(1b) protruded at the outer diameter of a linear tube unit; a tip housing(2) having a tip inlet hole(2a) fitted and combined with the tip and a key hole-shaped projection groove(2c) and an anti-rotation projection(2b) formed on a part fitted into a main housing(3); and the main housing fitted with the tip housing and provided with a projection groove(3c) formed at the housing inlet hole. All parts are combined to prevent the tip from idling or rotating in the pen.
