A semiconductor device capable of incorporating an element configured to accept and emit light having a short wavelength and a manufacturing method thereof are provided. A semiconductor element is housed in an enclosure which includes a bottom portion and side portions and having an aperture on an upper part thereof. Leads are buried in the bottom portion, and an end of each of the leads is arranged so as to approach the semiconductor element. The semiconductor element is connected to the leads by use of metal wires. The aperture of the enclosure is covered with a lid made of a transparent material for transmitting light accepted or emitted by the semiconductor element.