Next, configurations and functions of three first component mounting device MC6, second component mounting device MC7, and third component mounting device MC8 will be described with reference to FIG. 3. These devices have the same configuration, so that third component mounting device MC8 is illustrated as a representative example in the description. First component mounting device MC6 and second component mounting device MC7 also have the same configuration and function. Similarly, only a cross section of board transport line LA (lane A) is illustrated in board transport lines LA and LB having the same configuration, but the same applies to board transport line LB (lane B).

Third component mounting device MC8 includes a board transporter having a configuration in which a plurality of conveyor units (carry-in conveyor 6, work station conveyors 7#1 and 7#2, and carry-out conveyor 8) for transporting board 14 are disposed in series. In third component mounting device MC8, the board transporters are provided in each of board transport lines LA and LB. That is, third component mounting device MC8 includes at least one of the board transporters constituting a part of board transport lines LA and LB for transporting boards 14 from the upstream to the downstream in component mounting system 1.