PURPOSE: To know suction error without recourse to a nozzle cap by warning when the number of times of unsuction until individual nozzles reaching specified numbers of times of suction becomes a first specified number.

CONSTITUTION: The stop position of a device head 15, which sucks and takes out a part 8 from a feeder 8, is a suction station, and a suction nozzle 14 sucks the part 15. The stop position of the mounting head 14 one before the suction head is a suction compensating station, and a suction compensator 191 compensates the position of the suction head 191 in the Y direction being the direction perpendicular to the shifting direction of a supply stage 7. In the next but one stop position of the suction station, the judgment on whether the part is sucked or not and the detection of standing of the part 5 are performed. A warning means issues a warning when the number of times of unsuction until individual nozzles 14 reaching the specified numbers of times of suction becomes the first specified number, and a control means skips when the number of times of unsuction until its reaching other number of times of unsuction larger than the specified number of times of suction becomes a second specified number.