To precisely load a part by obtaining a deviation amount between the land picture of a substrate before the part is mounted and a target loading position, loading the part on the substrate, obtaining the deviation amount between the part picture and the target loading position, averaging the deviation amount of both positions.

The face of the substrate is divided into plural view areas and first and second views which are detached most are selected. The first view is image-picked up with a camera and the substrate and the camera are moved so that an inspection frame W is matched with the land picture R. Then, a shift amount XR1 and a shift amount CR1 are obtained and the shift amount is similarly obtained on the second view so as to set it to be the first correction amount. Then, the part is experimentally loaded on the substrate in accordance with the first correction amount and the substrate and the camera are moved so that the inspection frame W is matched with the part picture B. A shift amount XB1 and a shift amount CB1 are obtained and the shift amounts are similarly obtained on all the remaining views so as to set them to be the second correction amounts. Then, the first and second correction amounts are averaged, a final correction amount is obtained and the part is loaded on the substrate.