A locking device on two bodies (2, 4) slidingly movable relative to each other on a sliding track, one of which, the sliding body is movable in the sliding direction on the sliding track of the other, the guiding body, and in an end position is lockable and form-fittingly connectable to the guiding body by the locking device, wherein the locking device has a locking pin, which, in the sliding body, movable transversely to the sliding track in a straight guide, is form-fittingly guided transversely to the movement direction, between a neutral position, in which it retracts into the contour of the sliding body in the region of the sliding track, and a locking position, in which it cooperates with an engagement of the guiding body and form-fittingly locks the relative sliding movement of the sliding body in the sliding direction, characterized in that a socket spanner in the sliding body is straightly guided in a sliding manner parallel to its sliding direction, with a relative movement in the closing direction and an unlocking device, that the locking pin with an operating end protrudes in a pocket of the socket spanner, that the pocket cooperates with the locking pin, • with an unlock-action pairing (30,20) out of two edges and/or surfaces slidingly movable relatively to each other (driving-in surface), which lie in the plane stretched by the straight guide of the locking pin and the sliding track of the sliding body, and which have operation direction for a straight guidance of the locking pin -preferably inclined at 45°, • as well as with a push-action pairing with a pushing-edge, which is formed on the pocket transversely to the sliding direction of the sliding body and transversely to the insertion direction, and which engages the straightly guided region of the locking pin in the closing direction, o so that by the movement of the socket spanner, in the unlock direction, initially the locking pin is drivable into its neutral position and then the sliding body is movable in the sliding direction by the form-fitting engagement of the pushing edge simultaneously with the socket spanner, but independently of the guiding body; • with a drive-out-action pairing out of two relatively edges and/or surfaces slidingly movable on each other (driving-out edges, driving-out surface), which lie in the plane stretched by the straight guide of the locking pin and the sliding track of the sliding body, and which have an operating direction for the straight guide of the locking pin -preferably inclined at 45°, of which one driving out surface is inclined for the straight guide of the locking pin -preferably at 45°, and which, on the side facing away from the driving-out edge and the unlock-action pairing- in the closing direction - is formed, on the one hand, at the pocket and on the other hand, on the locking pin; • as well as with a lock-action pairing with a locking surface, which is formed subsequently to the drive-out-action pairing (17,18) on the pocket, transversely to the straight-guide of the locking pin, and which engages the operating end of the locking pin in its locking position, o so that by the movement of the socket spanner initially the locking pin in closing direction can be driven into its locking position and therein by the locking surface can be form-fittingly fixed. • with an unlock-action pairing (30,20) out of two edges and/or surfaces slidingly movable relatively to each other (driving-in surface), which lie in the plane stretched by the straight guide of the locking pin and the sliding track of the sliding body, and which have operation direction for a straight guidance of the locking pin -preferably inclined at 45°, • as well as with a push-action pairing with a pushing-edge, which is formed on the pocket transversely to the sliding direction of the sliding body and transversely to the insertion direction, and which engages the straightly guided region of the locking pin in the closing direction, o so that by the movement of the socket spanner, in the unlock direction, initially the locking pin is drivable into its neutral position and then the sliding body is movable in the sliding direction by the form-fitting engagement of the pushing edge simultaneously with the socket spanner, but independently of the guiding body; • with a drive-out-action pairing out of two relatively edges and/or surfaces slidingly movable on each other (driving-out edges, driving-out surface), which lie in the plane stretched by the straight guide of the locking pin and the sliding track of the sliding body, and which have an operating direction for the straight guide of the locking pin -preferably inclined at 45°, of which one driving out surface is inclined for the straight guide of the locking pin -preferably at 45°, and which, on the side facing away from the driving-out edge and the unlock-action pairing- in the closing direction - is formed, on the one hand, at the pocket and on the other hand, on the locking pin; • as well as with a lock-action pairing with a locking surface, which is formed subsequently to the drive-out-action pairing (17,18) on the pocket, transversely to the straight-guide of the locking pin, and which engages the operating end of the locking pin in its locking position, o so that by the movement of the socket spanner initially the locking pin in closing direction can be driven into its locking position and therein by the locking surface can be form-fittingly fixed.