A manufacturing method of a lens layer, including a first layer and a second layer for an electro-optical device, includes forming a first transmissive layer at a concave surface of an translucency insulating layer, forming, with a different material from the first transmissive layer, a first sacrificial layer on first transmissive layer, polishing its surface, to form a first layer being a residual portion of the first transmissive layer and a sacrificial layer residual portion being a residual portion of the first sacrificial layer, removing the sacrificial layer residual portion, forming a second transmissive layer at the first layer, forming, using a different material from the second transmissive layer, a second sacrificial layer on the second transmissive layer, and polishing the second transmissive layer and the second sacrificial layer to form a second layer from the second transmissive layer.