A cold end and a hot end are demarcated in a first thermoelectric semiconductor member. A first member made from metal or a semiconductor is connected to the cold end of the first thermoelectric semiconductor member. The first member is made from a material wherein, heat absorption occurs when first carriers comprising either electrons or holes are injected from the first member into the first thermoelectric semiconductor member. The first carriers transported to the hot end of the first thermoelectric semiconductor member are gathered into a light-emitting region. The light-emitting region is made from a semiconductor material. In this light-emitting region, light emission due to recombination between electrons and holes occurs.