To provide an electro-optical device, which is capable of improving film thickness uniformity and flatness of electro-optical layers to be formed. A method of manufacturing an electro-optical device according to the present invention comprises a step of forming a first partition wall portion and a second partition wall portion, and a step of ejecting a liquid substance for each of openings of each of the partition wall portions using a liquid droplet ejecting method, the liquid substance including functional materials composing the electro-optical layers. The ejected liquid substance has different viscosities for each electro-optical layer. In the partition wall portion formation step, a surface area of a portion of the first partition wall portion projecting from the second partition wall portion becomes relatively small in a position at which the liquid substance having relatively low viscosity is ejected, and the surface area of the portion of the first partition wall portion projecting from the second partition wall portion becomes relatively large in a position at which the liquid substance having relatively high viscosity is ejected.