A component transfer device comprising: a component mounting tool mounted on a movable mounting head, the component mounting tool being configured to collect a component from a component supply device and mount the component on a board; a side imaging section configured to image the component held by the component mounting tool from the side; characterized in that: a cleaning nozzle having an emission port only on a side surface of the cleaning nozzle that opens toward the side imaging section; and a positive pressure air supply section configured to supply positive pressure air to the cleaning nozzle and blow out the positive pressure air from the emission port toward the side imaging section; at least one of the cleaning nozzle and the mounting head is configured to perform a rotation operation and a raising and lowering operation in a state in which the positive pressure air is being supplied to the cleaning nozzle; wherein the side imaging section includes a lighting section configured to illuminate the component during imaging and a light path section that is configured to connect the component and the image detection unit, and at least one of the cleaning nozzle and the mounting head is configured to temporarily stop or decelerate at least one of a rotation speed and a raising and lowering speed at a position where the emission port faces the light path section at least one of a start timing, an intermediate timing, and an end timing of the rotation operation and the raising and lowering operation. a component mounting tool mounted on a movable mounting head, the component mounting tool being configured to collect a component from a component supply device and mount the component on a board; a side imaging section configured to image the component held by the component mounting tool from the side; characterized in that: a cleaning nozzle having an emission port only on a side surface of the cleaning nozzle that opens toward the side imaging section; and a positive pressure air supply section configured to supply positive pressure air to the cleaning nozzle and blow out the positive pressure air from the emission port toward the side imaging section; at least one of the cleaning nozzle and the mounting head is configured to perform a rotation operation and a raising and lowering operation in a state in which the positive pressure air is being supplied to the cleaning nozzle; wherein the side imaging section includes a lighting section configured to illuminate the component during imaging and a light path section that is configured to connect the component and the image detection unit, and at least one of the cleaning nozzle and the mounting head is configured to temporarily stop or decelerate at least one of a rotation speed and a raising and lowering speed at a position where the emission port faces the light path section at least one of a start timing, an intermediate timing, and an end timing of the rotation operation and the raising and lowering operation. a cleaning nozzle having an emission port only on a side surface of the cleaning nozzle that opens toward the side imaging section; and a positive pressure air supply section configured to supply positive pressure air to the cleaning nozzle and blow out the positive pressure air from the emission port toward the side imaging section; at least one of the cleaning nozzle and the mounting head is configured to perform a rotation operation and a raising and lowering operation in a state in which the positive pressure air is being supplied to the cleaning nozzle; wherein the side imaging section includes a lighting section configured to illuminate the component during imaging and a light path section that is configured to connect the component and the image detection unit, and at least one of the cleaning nozzle and the mounting head is configured to temporarily stop or decelerate at least one of a rotation speed and a raising and lowering speed at a position where the emission port faces the light path section at least one of a start timing, an intermediate timing, and an end timing of the rotation operation and the raising and lowering operation.