A biopsy gun having a cannula and a stylet guided in the cannula comprises the following a housing, a cannula carriage for moving the cannula, a stylet carriage for moving the stylet, a tensioning grip for tensioning the cannula carriage and the stylet carriage from an initial position into a tensioning position, and an engaging member that is provided on the tensioning grip and has recesses adapted to engage with corresponding projections of the cannula carriage and the stylet carriage. The engaging member is rotatably attached to the tensioning grip and is biased by a spring against a contact surface of the housing.
