Machine tool having a movable tool carrier configured to be equipped with tool holders and comprising receptacles for tool holders, wherein each tool holder and the tool carrier comprise support surfaces (10, 18) assigned to each other and devices for mounting the tool holder to the tool carrier and wherein adjustment means (12, 13) are provided for accurately positioning the tool holder with respect to a receptacle assigned thereto, and wherein the devices for mounting the tool holder comprise at least one tie rod extending orthogonal to the support surface (10, 18) of the tool holder or the tool carrier, and wherein the tool holder and/or the tool carrier have a clamping device assigned thereto, which, when the tool holder is inserted into the receptacle, is configured to engage the respective tie rod during a clamping process and to exert an axial clamping force thereon, with which the support surfaces (10, 18) of the tool holder and the tool carrier are pressed against one another, wherein the clamping device comprises at least one clamping element which is mounted on the tool carrier transversely to the tie rod and is adjustable between a clamping position and a release position, which clamping element carries a first clamping surface, wherein a second clamping surface is provided on the tie rod, characterized in that the second clamping surface is in self-locking engagement with the first clamping surface of the clamping element in the clamping position, the tie rod is elastically deformable to a limited extent in the axial direction and, when the clamping element is in the clamping position, is stretched via the clamping surfaces (24, 35), which are engaging each other, to an extent that generates the required axial clamping force, the clamping element can be coupled to an adjusting device assigned to the tool carrier by means of a coupling (29, 30) which is controllable depending on the movement of the tool carrier, wherein the clamping element is adjustable between its clamping position and its release position by the adjusting device, the tool carrier is movable at least into a machining position for a tool holder arranged on one of its receptacles and into a tool holder changing position, the adjusting device actuating the clamping element is arranged in the area of the tool holder changing position and is firmly installed in the machine tool and is coupled to the clamping element via the releasable coupling (29, 30). wherein the devices for mounting the tool holder comprise at least one tie rod extending orthogonal to the support surface (10, 18) of the tool holder or the tool carrier, and wherein the tool holder and/or the tool carrier have a clamping device assigned thereto, which, when the tool holder is inserted into the receptacle, is configured to engage the respective tie rod during a clamping process and to exert an axial clamping force thereon, with which the support surfaces (10, 18) of the tool holder and the tool carrier are pressed against one another, wherein the clamping device comprises at least one clamping element which is mounted on the tool carrier transversely to the tie rod and is adjustable between a clamping position and a release position, which clamping element carries a first clamping surface, wherein a second clamping surface is provided on the tie rod, characterized in that the second clamping surface is in self-locking engagement with the first clamping surface of the clamping element in the clamping position, the tie rod is elastically deformable to a limited extent in the axial direction and, when the clamping element is in the clamping position, is stretched via the clamping surfaces (24, 35), which are engaging each other, to an extent that generates the required axial clamping force, the clamping element can be coupled to an adjusting device assigned to the tool carrier by means of a coupling (29, 30) which is controllable depending on the movement of the tool carrier, wherein the clamping element is adjustable between its clamping position and its release position by the adjusting device, the tool carrier is movable at least into a machining position for a tool holder arranged on one of its receptacles and into a tool holder changing position, the adjusting device actuating the clamping element is arranged in the area of the tool holder changing position and is firmly installed in the machine tool and is coupled to the clamping element via the releasable coupling (29, 30).