A biopsy gun having a cannula and a stylet guided in the cannula, the biopsy gun further comprising: 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 to a tensioning position, an engagement element which is provided on the tensioning grip and has recesses (9, 10) which can engage with corresponding projections (11, 12) of the cannula carriage and the stylet carriage, wherein the engagement element is rotatably mounted on the tensioning grip and is pretensioned against a contact surface of the housing by means of a spring, the tensioning grip has a section which rotatably supports the engagement element and has a spring-receiving hole, the engagement element has a spring-receiving groove, a first end of the spring is inserted into the spring-receiving groove and a second end of the spring is inserted into the spring-receiving hole, wherein the engagement element has a cannula-side recess and a stylet-side recess, the cannula carriage has a cannula-side projection and the stylet carriage has a stylet-side projection, wherein the cannula-side projection is closer to the engagement element than the stylet-side projection, at least in the initial position, wherein the engagement element, the contact surface, the cannula-side projection and the stylet-side projection are designed such that, in the non-actuated position of the tensioning grip, the engagement element is held by the spring and the contact surface in such a rotational position that the cannula-side recess is engaged with the cannula-side projection, so that, when the tensioning grip is actuated, the engagement element is rotated towards the side of the cannula-side projection by the engagement between the cannula-side recess and the cannula-side projection against the spring force, so that the stylet-side recess cannot engage with the stylet-side projection when the cannula carriage is tensioned. 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 to a tensioning position, an engagement element which is provided on the tensioning grip and has recesses (9, 10) which can engage with corresponding projections (11, 12) of the cannula carriage and the stylet carriage, wherein the engagement element is rotatably mounted on the tensioning grip and is pretensioned against a contact surface of the housing by means of a spring, the tensioning grip has a section which rotatably supports the engagement element and has a spring-receiving hole, the engagement element has a spring-receiving groove, a first end of the spring is inserted into the spring-receiving groove and a second end of the spring is inserted into the spring-receiving hole, wherein the engagement element has a cannula-side recess and a stylet-side recess, the cannula carriage has a cannula-side projection and the stylet carriage has a stylet-side projection, wherein the cannula-side projection is closer to the engagement element than the stylet-side projection, at least in the initial position, wherein the engagement element, the contact surface, the cannula-side projection and the stylet-side projection are designed such that, in the non-actuated position of the tensioning grip, the engagement element is held by the spring and the contact surface in such a rotational position that the cannula-side recess is engaged with the cannula-side projection, so that, when the tensioning grip is actuated, the engagement element is rotated towards the side of the cannula-side projection by the engagement between the cannula-side recess and the cannula-side projection against the spring force, so that the stylet-side recess cannot engage with the stylet-side projection when the cannula carriage is tensioned.