PURPOSE: A lighting device is provided to have no use for a separate heat radiation by exposing a part of circuit board which acts as a heat radiation plate to the outside. CONSTITUTION: A circuit board(110) has a structure inserted into a cylindrical cover(120). A light emitting device is mounted on the first surface of a circuit board. The light generated from the light emitting device passes through the cover. An opening is formed on the upper part of the cover in the longitudinal direction of the cylinder. A part of a second surface(112) of the circuit board is exposed to the outside through the opening.
