Abstract: A machine tool comprises at least one revolvable spindle having an end for supporting a work piece, a first processing tool disposed opposite to the end of the spindle for processing the work piece, a second processing tool disposed parallel to the first processing tool, and a revolving unit for revolving the spindle about a central revolving axis to place the end of the spindle opposite to the second processing tool for processing the work piece. A chamber is disposed on the outer peripheral surface of the work spindle. A pair of inlet and outlet connections are revolved integrally with the work spindle and are arranged on opposite sides of the central revolving axis. Connecting pipes connect the inlet and outlet connection on one side of the central revolving axis to the inlet and outlet connection at the opposite side of the central revolving axis through the chamber. A coolant supply pipe is provided for supplying a coolant to the chamber through the inlet and outlet connections and the connecting pipes.