According to one embodiment, a display device includes a first substrate including as insulating substrate with a first through hole, a pad electrode positioned above the insulating substrate, and a signal line electrically connected to the pad electrode, a second substrate opposed to the first substrate, a sealant which adheres the first substrate and the second substrate, a line substrate including a connection line and disposed below the insulating substrate, and a conductive material which electrically connects the pad electrode and the connection line, wherein the sealant is less absorptive than is the insulating substrate as to a wavelength less than 350 nm.