In a parts mounting apparatus, a suction nozzle (18) is caused to perform a cycloid movement. A part (7) such as an electronic part is sucked into the nozzle (18) at one of bottom dead points of the cycloid movement and mounted onto another component such as a circuit substrate at the other or another bottom dead point. In compensation of the position of the nozzle (18) at the bottom dead point, the nozzle (18) is also caused to perform the cycloid movement. The position of the nozzle (18) at the bottom dead point is monitored by a monitoring camera (70) so that an amount of deviation of the position of the nozzle (18) from the bottom dead point is obtained. The phase of the cycloid movement is compensated so that the amount of deviation of the nozzle (18) is rendered zero. Alternatively, the part (7) sucked in the nozzle (18) positioned at the bottom dead point is monitored by the monitoring camera (70).