A method for detecting positions of a plurality of electrode pads of semiconductor chips formed on a semiconductor wafer includes: setting an imaging target region greater than a semiconductor chip on the semiconductor wafer; performing split imaging so as to entirely cover the imaging target region; and detecting positions of electrode pads of the semiconductor chip by processing images obtained by the split imaging. The split imaging is performed by using an imaging device which enlarges and images a region smaller than the imaging target region by one imaging.