A machine tool 1 includes a turret (4, 104) to which a tool unit 2 is adapted to be radially mounted, a cylindrical turret pivoting driving shaft (5, 105) for transmission of pivoting driving force to the turret (4, 104), a rotary tool driving shaft (8, 108) adapted to be rotated with respect to an indexing axis for transmission of rotation driving force to a tool (7, 107) of a rotary tool unit (2b, 102b) mounted on the turret (4, 104), and a unit pivoting driving shaft (12, 112) adapted to be rotated with respect to the indexing axis independently of the rotary tool driving shaft (8, 108) for transmission of pivoting driving force to the rotary tool unit (2b, 102b) mounted on the turret (4, 104) to change the direction of the rotation axis AX2 of the tool (7, 107). The rotary tool driving shaft and the unit pivoting driving shaft are coaxially arranged inside the turret pivoting driving shaft.