An electro-optical device formed on a semiconductor substrate, includes: a first transistor controlling a current level according to a voltage between a gate and a source; a second transistor electrically connected between a data line and the gate of the first transistor; a third transistor electrically connected between the gate and a drain of the first transistor; and a light-emitting element emitting light at a luminance according to the current level, in which one of a source and a drain of the second transistor and one of a source and a drain of the third transistor are formed by a common diffusion layer.