A vertical machining center, which comprises a pallet clamp unit and a pallet conveyor unit arranged along the front face of the bed. A saddle is provided on the upper surface of the bed, with the saddle being slidable along the X axis. A column is provided on the top surface of the saddle, with the column being slidable along the Y axis. A headstock is provided on the front face of the column, with the headstock being vertically slidable. A tool magazine and an automatic tool exchange device are both arranged alongside the bed, and a numerical control unit is provided for numerically controlling the saddle, the column, the headstock, the pallet clamp unit, the pallet conveyor, the tool magazine and the automatic tool exchange device.