Abstract: A first camera detects a positional relationship among first, second and third nozzles. A second camera detects pick-up positions of chips in parts feeders. Tolerance zones for the respective chips are determined, within which the nozzle can pick up the chip. When one of nozzles is placed in the corresponding pick-up position, it is judged whether or not other nozzles are located within the corresponding tolerance zones, respectively. If the judgment result is "YES", the nozzles pick up the chips simultaneously , and if this result is "NO", the nozzles pick up the chips separately.

Abstract: An electronic component mounting apparatus for determining whether or not a nozzle replacement operation is successfully performed. A horizontal array of nozzles are accommodated in the holder in a nozzle stocker, and a light emitting device and a light receiving device are arranged so that the light path between both runs above the nozzles. The nozzle stocker is arranged in a travel path of a feeding head. The nozzle mount of the feeding head returns a used nozzle into the holder or mounts a new nozzle thereon. When any nozzle remains lifted from the holder intercepting the light path, a returning operation of the used nozzle is determined to be a failure. When a nozzle replacement is performed, its success or failure is reliably determined by detecting a intercepting height of light and release height of light by the nozzle and nozzle mount, respectively.