The invention seeks to provide a method for implementing a gray-scale display of an electro-optical device according to a time ratio gray-scale method without providing reset lines. In an electro-optical device comprising, at an intersection of a scanning line and a data line, an electro-optical element, a driving transistor for driving the electro-optical element, a switching transistor for controlling the driving transistor, and a reset transistor having the function of resetting the driving transistor to a non-conducting state, a gray-scale is obtained by performing a plurality of set-reset operations, each set-reset operation comprising: a setting step of supplying an on-signal to the switching transistor via the scanning line, and of supplying a set signal for selecting a conducting state or a non-conducting state of the driving transistor to the driving transistor via the data line and the switching transistor in accordance with the on-signal; and a resetting step of supplying an on-signal for the reset transistor via the scanning line so as to reset the driving transistor to the non-conducting state.