The height measurement region capable of being detected by a height detection sensor (8) is limited so that only the connection portions are detected and other noise objects are not detected. A luminance image capturing means (3) for obtaining luminance image data of the entire bottom surface of an electronic component (2) and a height image capturing means (8) for obtaining height image data of the entire bottom surface of the electronic component (2) are provided. The positional detection of the electronic component (2) is executed by individually selectively using two-dimensional positional detection by the luminance image capturing means (3) and three-dimensional positional detection by the height image capturing means (8). A height image of the entire bottom portion of an electronic component (2) having a plurality of bump electrodes (2a) in the bottom portion is captured as two-dimensional height image data by the height detection sensor (3) and the individual bump electrodes (2a) are extracted from the height image data so as to detect the volume or shape of individual bump electrodes (2a). When the volume or shape of the bump electrodes (2a) does not satisfy a predetermined criterion, the electronic component (2) is regarded as abnormal. <IMAGE>
