It is an object to provide a planar lighting device that is a thin and light in weight, that emits light without luminous unevenness and that is capable of achieving increased dimensions. A particular method includes receiving an operating system independent function call at a web server. The cold deposition step need only be performed for a time sufficient to deposit metal over the entire surface on which the metal layer is to be formed. The emulator also has a simulation environment interface for exchanging data andor events with the simulation environment. The Nch depletion mode MOS transistor has electrical characteristics such that a source voltage thereof is higher than a silicon substrate voltage thereof and a saturation current of the Nch depletion mode MOS transistor is decreased.