A work machine includes a control device including a lead position detecting section to detect a lead position which is positions of a pair of leads based on imaged data imaged by an imaging device, a first detecting region setting section to set, based on the lead position detected by the lead position detecting section, a first detecting region outside the pair of leads including a part of a bottom section outside the pair of leads, a second detecting region outside the pair of leads, being opposed to the first detecting section across the pair of leads including a part of the bottom section, and a polarity determining section configured to determine the polarity of the pair of leads based on whether the mark portion exists in each of the first detecting region and the second detecting region.