A substrate for an electro-optical device having a planarization layer, comprising:
- a substrate;
- a plurality of sub-interlayer-film wiring patterns formed in film formation layers disposed above the substrate;
- interlayer films interlayered amongst the plurality of sub-interlayer-film wiring patterns, at least one of the interlayer films having a planarized surface;
- a plurality of contact holes formed in the planarized interlayer film corresponding to portions of the plurality of sub-interlayer-film wiring patterns;
- and
- a stacked film formed between the substrate and the plurality of sub-interlayer-film wiring patterns and whose portions corresponding to each region of the plurality of contact holes being equal or nearly equal in thickness.