A component mounter comprising: a mounting head configured to pick up components and mount the components onto a substrate, a rotatory head moving device configured to move the mounting head in parallel to a horizontal plane, and a conveyance device configured to convey the substrate in a conveyance direction parallel to the horizontal plane; wherein the mounting head includes multiple nozzles provided at predetermined intervals along a circumference of the mounting head configured to pick up and hold the components by a negative pressure, multiple switching valves provided corresponding to each of the multiple nozzles and configured to switch whether the negative pressure is supplied to the corresponding nozzle, a nozzle moving device configured to change which nozzle is positioned at each of a first nozzle position and a second nozzle position for moving the multiple nozzles and performing at least one of picking up and mounting of the components, a first driving device having a first driving source and configured to switch the switching valve that corresponds to the nozzle positioned at the first nozzle position by a driving force from the first driving source, and a second driving device having a second driving source, and configured to switch the switching valve that corresponds to the nozzle positioned at the second nozzle position by a driving force from the second driving source, characterized in that the second driving source is disposed on a side opposite to the first driving source so as to sandwich the multiple nozzles along a direction parallel to the horizontal plane and orthogonal to the conveyance direction. a mounting head configured to pick up components and mount the components onto a substrate, a rotatory head moving device configured to move the mounting head in parallel to a horizontal plane, and a conveyance device configured to convey the substrate in a conveyance direction parallel to the horizontal plane; wherein the mounting head includes multiple nozzles provided at predetermined intervals along a circumference of the mounting head configured to pick up and hold the components by a negative pressure, multiple switching valves provided corresponding to each of the multiple nozzles and configured to switch whether the negative pressure is supplied to the corresponding nozzle, a nozzle moving device configured to change which nozzle is positioned at each of a first nozzle position and a second nozzle position for moving the multiple nozzles and performing at least one of picking up and mounting of the components, a first driving device having a first driving source and configured to switch the switching valve that corresponds to the nozzle positioned at the first nozzle position by a driving force from the first driving source, and a second driving device having a second driving source, and configured to switch the switching valve that corresponds to the nozzle positioned at the second nozzle position by a driving force from the second driving source, characterized in that the second driving source is disposed on a side opposite to the first driving source so as to sandwich the multiple nozzles along a direction parallel to the horizontal plane and orthogonal to the conveyance direction.