The invention relates to a surgical sliding shaft instrument that can be dismantled and has a function shaft (2, 3) comprising a guide element (2), a slide element (3) that is supported on the guide element (2) in a sliding manner and has a coupling element (17), an undercut rail (22) oriented along the sliding direction of the slide element (3), which rail has a mounting opening (22) at the proximal end of the rail, and a profile web (23) having a profile that is complementary to the rail (22). The surgical sliding shaft instrument further comprises a gripping part (4, 5), which has a rear gripping element (4) that is arranged at an angle at the end of the guide element (2), a front gripping element (5) that is pivotably supported on the guide element (2), which front gripping element has a carrier element (16) that is designed to carry along the coupling element (17), and a securing device (15) arranged on the rear gripping element (4), which securing device engages with a form closure component (14) in the proximal part (8) of the guide groove (6) in a securing position. According to the invention, a transition piece (10) complementary to the form closure component (14) is arranged between the distal part (9) and the proximal part (8). Thus, a considerable increase in the locking security can be achieved in a structurally simple manner.
