A display device according to one aspect of the present invention includes a first substrate including a pixel portion and a terminal portion, a second substrate arranged to face the pixel portion, a first light source device arranged in the terminal portion, and irradiating a first end surface of the second substrate with first light, a liquid crystal layer arranged between the first substrate and the second substrate, and a semiconductor element arranged on a side opposite to a side of the pixel portion across the first light source device, and electrically coupled with the terminal portion, wherein the first light is propagated while reflected between the first substrate and the second substrate, and the liquid crystal layer modulates the propagated first light.