A component mounting system comprising: a component mounter (M3, M4, M5, M6) configured to mount a component in a board; a component feeder that is placed in the component mounter (M3, M4, M5, M6) and configured to supply the component; a mobile component supply device configured to hold at least one container storing a component, to automatically move, and to supply the component in the at least one container to the component feeder; a component storage configured to store the at least one container, wherein the component mounter (M3, M4, M5, M6) includes a container holding device configured to hold the at least one container, and wherein the mobile component supply device includes a container housing unit configured to house the at least one container, and a container mover (58, 61) configured to move the at least one container between the container housing unit and the container holding device and between the container housing unit and the component storage, characterized in that the mobile component supply device further includes a supporter configured to support the container housing unit from below so as to move freely in a horizontal direction and a vertical direction, and a traveller including the supporter on the top and configured to move or stop automatically, the component mounter (M3, M4, M5, M6) includes a coupler being coupled to the container housing unit and configured to hold the container housing unit, and when the at least one container is moved by the container mover (58, 61) between the container housing unit and the container holding device, the traveller is configured to stop the mobile component supply device at a predetermined stop position with respect to the component mounter (M3, M4, M5, M6), and the coupler is configured to couple to the container housing unit and to hold the container housing unit. a component mounter (M3, M4, M5, M6) configured to mount a component in a board; a component feeder that is placed in the component mounter (M3, M4, M5, M6) and configured to supply the component; a mobile component supply device configured to hold at least one container storing a component, to automatically move, and to supply the component in the at least one container to the component feeder; a component storage configured to store the at least one container, wherein the component mounter (M3, M4, M5, M6) includes a container holding device configured to hold the at least one container, and wherein the mobile component supply device includes a container housing unit configured to house the at least one container, and a container mover (58, 61) configured to move the at least one container between the container housing unit and the container holding device and between the container housing unit and the component storage, characterized in that the mobile component supply device further includes a supporter configured to support the container housing unit from below so as to move freely in a horizontal direction and a vertical direction, and a traveller including the supporter on the top and configured to move or stop automatically, the component mounter (M3, M4, M5, M6) includes a coupler being coupled to the container housing unit and configured to hold the container housing unit, and when the at least one container is moved by the container mover (58, 61) between the container housing unit and the container holding device, the traveller is configured to stop the mobile component supply device at a predetermined stop position with respect to the component mounter (M3, M4, M5, M6), and the coupler is configured to couple to the container housing unit and to hold the container housing unit.