Abstract: Disclosed is a rib spreader including a stationary arm having a first bent portion; a first hook having a contact surface to contact with one incision plane of a sternum of human, and attached to the stationary arm ahead of the first bent portion so as to be pivotable over a predetermined angular range; a rack fixed to the base end of the stationary arm at a predetermined angle and curved archwise; a movable arm supported at the base end of the movable arm by the rack so as to be movable along the rack, to thereby vary the distance from the stationary arm; and a second hook having a contact surface to contact with the other incision plane, and is attached to the movable arm ahead of the second bent portion so as to be pivotable over a predetermined angular range.