An electro-optical device encased in a mounting case includes an electro-optical device in which projection light from a light source is incident on an image display region; and a mounting case including a plate disposed to face one surface of the electro-optical device and a cover to cover the electro-optical device, the cover having a first abutting portion of abutting against the plate, the mounting case accommodating the electro-optical device by holding at least a portion of a peripheral region located in the circumference of the image display region of the electro-optical device with at least one of the plate and the cover. Further, at least one of a heat transfer path reaching the cover from the electro-optical device through the plate and another heat transfer path reaching the cover from the electro-optical device not through the plate is formed, and the heat transfer path includes a portion in which the electro-optical device area contacts with the cover, directly or indirectly.