Abstract: A machine tool having pallets each being movable between machining region and non-machining region. At the machining region, there are provided a movable column which supports a spindle head, and a stationary table confronting the column. In front of the stationary table, a workpiece handling station is provided which defines the non-machining region. When one of the pallets is positioned at the machining region for machining to the one of the workpieces, another pallet is brought to the non-machining region, where already machined workpiece is replaced by a new workpiece, and the another pallet is again introduced into the machining region while the first workpiece is still subjected to machining. Machining to the new workpiece is achievable by simply moving the column within the machining region.