There is provided a component mounter including: a plurality of transport lanes for transporting a board sorted by a board sorting device; a congestion index calculator for calculating a congestion index indicating a congestion degree of each of the plurality of transport lanes; a transport lane determiner for determining a transport lane for carrying in the board among the plurality of transport lanes based on the calculated congestion index; and an outputter for outputting a board request signal for requesting to carry the board into the transport lane determined by the transport lane determiner, to the board sorting device.