A mounting device used in a mounting system including multiple mounting devices, the mounting device comprising: a supply section configured to hold a component wherein the supply section is provided with a holding member (25; 26) holding the component; a mounting section configured to pick up the component from the supply section and perform a mounting process for the component on a mounting target; an inspection/imaging section configured to capture an image of the mounting target; and a control section configured to: - execute a missing component inspection process of detecting whether a component on the mounting target is missing or not by using a captured image of the mounting target, and, - control, when a component is missing, the mounting section to pick up the missing component from the supply section and dispose the missing component on the mounting target; characterized in that the mounting system further includes a mobile work device including an accommodation section configured to accommodate the holding member to collect the holding member from the supply section and/or to move the holding member to the supply section, and the control section is further configured to: - execute the missing component inspection process on the mounting target that has been subjected to a mounting process by other mounting device, and - control, when a component is missing, the mounting section to pick up the missing component that should have been mounted by the other mounting device from the supply section and dispose the missing component on the mounting target, so as to cause the mobile work device to move the holding member holding the missing component to the supply section when a component on the mounting target is missing and the missing component is not present in the supply section. a supply section configured to hold a component wherein the supply section is provided with a holding member (25; 26) holding the component; a mounting section configured to pick up the component from the supply section and perform a mounting process for the component on a mounting target; an inspection/imaging section configured to capture an image of the mounting target; and a control section configured to: - execute a missing component inspection process of detecting whether a component on the mounting target is missing or not by using a captured image of the mounting target, and, - control, when a component is missing, the mounting section to pick up the missing component from the supply section and dispose the missing component on the mounting target; - execute a missing component inspection process of detecting whether a component on the mounting target is missing or not by using a captured image of the mounting target, and, - control, when a component is missing, the mounting section to pick up the missing component from the supply section and dispose the missing component on the mounting target; characterized in that the mounting system further includes a mobile work device including an accommodation section configured to accommodate the holding member to collect the holding member from the supply section and/or to move the holding member to the supply section, and the control section is further configured to: - execute the missing component inspection process on the mounting target that has been subjected to a mounting process by other mounting device, and - control, when a component is missing, the mounting section to pick up the missing component that should have been mounted by the other mounting device from the supply section and dispose the missing component on the mounting target, - execute the missing component inspection process on the mounting target that has been subjected to a mounting process by other mounting device, and - control, when a component is missing, the mounting section to pick up the missing component that should have been mounted by the other mounting device from the supply section and dispose the missing component on the mounting target,