An automatic exchanging device moves along a front face of component mounting line in an arrangement direction of multiple component mounters to automatically exchange a feeder with respect to feeder setting section of each component mounter. A production management computer of the component mounting line or control device of each component mounter monitors an arrangement status of the feeder set in the feeder setting section of each component mounter, and when it is determined that an empty space of the feeder setting section of any one of the component mounters is equal to or larger than a predetermined value based on a monitoring result, controls an operation of the automatic exchanging device, such that an automatically exchangeable unit is set in the empty space of the feeder setting section of the component mounter.