A tensioning device of a surgical retractor has a tensioning section for applying a tensile force to a tool that is to be arranged thereon, and a holding bar fixed in position relative to the tensioning section, and also a locking device. The locking device is provided between the holding bar and the tensioning section and has a releasable locking function counter to the direction of the tensile force. The tensioning device can be operated comfortably, with minimal force being applied, is optimally accessible and takes up only a small overall volume. This is made possible by the fact that the locking device is configured as a linear ratchet or linear feed mechanism and that the feed mechanism has an actuating lever and an unlocking device.
