The system has an imaging unit configured to image a work space at a viewpoint position in a visual line direction of a worker together with a workpiece on which a component is mounted, a position attitude information obtaining unit configured to obtain a position attitude information which indicates a relative position attitude relation between the viewpoint of the worker and the workpiece in the work space, a virtual image generating unit configured to generate a three-dimensional virtual image indicating the component after being mounted at the viewpoint position in the visual line direction, an image composing unit configured to generate a composite image by superimposing the virtual image on a real image of the work space, and a display unit configured to display the composite image. According to the system, efficiency of the component mounting work can be considerably improved by using the mixed reality technology.