Abstract: An apparatus for positioning and clamping a transferrable work-clamp pallet on the movable table of a machine tool of vertical or horizontal type. The pallet clamping device is composed of a bed plate on the movable table of the machine tool having transfer rails, guide rails, pallet supporting blocks, positioning devices and clamping devices. The work-clamp pallet is transferred onto the bed plate by its castors rolling on the transfer rails and guided by the guide rails. After high-precision positioning by the positioning devices, the pallet is clamped onto the supporting blocks. Devices are also provided for confirming proper positioning and clamping of the work-clamp pallet and for blowing off chips deposited on the supporting blocks.