A component mounting machine comprising: a component supply device configured to supply a component to a supply position; a component transfer device configured to use a component mounting tool (452;462;472) to pick up the component from the supply position and mount the component on a board; a component detecting section configured to detect whether the component is present at the supply position before or while the component is being picked up by the component mounting tool (452;462;472); a holding detecting section configured to detect whether the component mounting tool (452;462;472) is holding the component following pickup; and a remaining detecting section configured to detect whether the component remains at the supply position; and a dropped determining section configured to determine whether the component has dropped based on a detection result of the component detecting section, a detection result of the holding detecting section, and a detection result of the remaining detecting section, wherein the dropped determining section is configured to determine that the component has dropped in a case in which the component detecting section detects that there is a component at the supply position, the holding detecting section detects that the component mounting tool (452;462;472) is not holding the component, and the remaining detecting section detects that the component is not remaining at the supply position, characterized in that the remaining detecting section is configured to detect whether the component remains at the supply position in a case in which it is detected by the holding detecting section that the component is not being held by the component mounting tool (452;462;472). a component supply device configured to supply a component to a supply position; a component transfer device configured to use a component mounting tool (452;462;472) to pick up the component from the supply position and mount the component on a board; a component detecting section configured to detect whether the component is present at the supply position before or while the component is being picked up by the component mounting tool (452;462;472); a holding detecting section configured to detect whether the component mounting tool (452;462;472) is holding the component following pickup; and a remaining detecting section configured to detect whether the component remains at the supply position; and a dropped determining section configured to determine whether the component has dropped based on a detection result of the component detecting section, a detection result of the holding detecting section, and a detection result of the remaining detecting section, wherein the dropped determining section is configured to determine that the component has dropped in a case in which the component detecting section detects that there is a component at the supply position, the holding detecting section detects that the component mounting tool (452;462;472) is not holding the component, and the remaining detecting section detects that the component is not remaining at the supply position, characterized in that the remaining detecting section is configured to detect whether the component remains at the supply position in a case in which it is detected by the holding detecting section that the component is not being held by the component mounting tool (452;462;472).