When recognizing leads by processing an image captured by a camera of a component provided with a single row or multiple rows of leads of the same size and shape at a regular pitch, waveform analysis of a change pattern of brightness (pixel value) along multiple lines set in a vertical, a horizontal, or a diagonal direction of the image is performed so as to identify a region in which the brightness changes cyclically as a lead recognition target region in which there is a possibility of a lead existing. Then, image recognition of leads is performed in the lead recognition target region.