<p>Monitor setting units (15) for detachably setting an operation monitor (14) are formed in the upper portion of a front cover (13) of multiple component mounting devices (12) that make up the component mounting line (11). An operation monitor (14) can be used common to all component mounting devices (12) as the operation unit and display unit of each of the multiple component mounting devices (12). The monitor setting units (15) are provided with an interface unit (16) which communicates with the operation monitor (14) when said operation monitor (14) is set, and the interface unit (16) is configured to supply power to the operation monitor (14) when the operation monitor (14) is set. The operation monitor (14) has a means for selecting multiple simultaneously operable component mounting devices (12) and is configured to be capable of operating the multiple component mounting devices (12) simultaneously with a single operation monitor (14).</p>
