When using a liquid droplet ejection method, a conventional photomask is not required, however, it is required instead that a moving path of a nozzle or a substrate is controlled with accuracy at least in ejecting liquid droplets. According to the characteristics of compositions to be ejected or their pattern, such ejection conditions are desirably set as the moving rate of a nozzle or a substrate, ejection quantity, ejection distance and ejection rate of compositions, atmosphere of the space that the compositions are ejected, the temperature and moisture of the space, and heating temperature of the substrate. A liquid droplet ejection system in accordance with the invention comprises an input means for inputting data of a thin film pattern, a set means for setting a nozzle for a ejecting a composition containing a material for forming the thin film or setting a moving path of the substrate to which the composition is ejected, an image pick-up means for detecting an alignment marker formed on a substrate and a control means for controlling the moving path of the nozzle or the substrate.