Abstract: The surgical instrument for applying linear staple sutures comprises a supporting body with a supporting jaw having staple bending depressions. The staple body of the instrument is traversable inside the U-shaped supporting body from its own drive. The staple magazine is accommodated in the staple body and has a longitudinal recess with an open end to receive U-shaped staples adapted to be expelled from said magazine slots by means of an ejector. Part of the supporting jaw which carries the staple bending depressions is made detachable and has a groove. The supporting body has an opening arranged symmetrically to the longitudinal recess with an open end, both said opening and said longitudinal recess establishing in combination the gap for passing the knife blade traversable along the groove to sever the tissue between the sutures applied.