A component mounter head unit comprising: a rotating head configured to be rotatable around an R shaft that extends in a vertical direction; multiple nozzle holders provided on the rotating head at specified intervals in a circumferential direction in a lowerable manner; multiple suction nozzles configured to pick up a component, each of the suction nozzles being held pointing downwards on the multiple nozzle holders; an R-axis driving mechanism configured to rotate the rotating head around the R shaft so as to revolve the multiple nozzle holders together with the multiple suction nozzles in the circumferential direction of the rotating head; a Q-axis driving mechanism configured to rotate each of the multiple nozzle holders around its own axis center line so as to correct a direction of each component held by each suction nozzle on each of the nozzle holders; and a Z-axis driving mechanism configured to individually lower the nozzle holders at a specified stopping position on a revolving path of the nozzle holders; wherein the R-axis driving mechanism includes an R-axis gear configured to rotate together with the rotating head around the R shaft, and an R-axis motor configured to rotate a driving gear that engages with the R-axis gear, and the R-axis gear is arranged on a lower surface of the rotating head, characterized by the R shaft is fixed to a main body frame of the head unit, and the rotating head is rotatably supported on the R-shaft and a head rotation support section configured to rotatably support an outer circumferential section of the rotating head is provided on the main body frame of the head unit. a rotating head configured to be rotatable around an R shaft that extends in a vertical direction; multiple nozzle holders provided on the rotating head at specified intervals in a circumferential direction in a lowerable manner; multiple suction nozzles configured to pick up a component, each of the suction nozzles being held pointing downwards on the multiple nozzle holders; an R-axis driving mechanism configured to rotate the rotating head around the R shaft so as to revolve the multiple nozzle holders together with the multiple suction nozzles in the circumferential direction of the rotating head; a Q-axis driving mechanism configured to rotate each of the multiple nozzle holders around its own axis center line so as to correct a direction of each component held by each suction nozzle on each of the nozzle holders; and a Z-axis driving mechanism configured to individually lower the nozzle holders at a specified stopping position on a revolving path of the nozzle holders; wherein the R-axis driving mechanism includes an R-axis gear configured to rotate together with the rotating head around the R shaft, and an R-axis motor configured to rotate a driving gear that engages with the R-axis gear, and the R-axis gear is arranged on a lower surface of the rotating head, characterized by the R shaft is fixed to a main body frame of the head unit, and the rotating head is rotatably supported on the R-shaft and a head rotation support section configured to rotatably support an outer circumferential section of the rotating head is provided on the main body frame of the head unit.