LIGHTING APPARATUS

A lighting device is provided to reduce an installation cost and a maintenance cost by including a first optical source for a main lighting function and a second optical source for guiding the emergency exit. A first optical source(120) irradiates the light to the inside of a light guide plate(110). The first optical source performs the main lighting function. A second optical source(132) is turned on when the first optical source is turned off. The second optical source irradiates the light to the upper side of the light guide plate. The second optical source performs the exit guidance function. A guide plate(140) is arranged between the second optical source and the light guide plate to guide the light irradiated from the second optical source. A reflective layer(150) reflects the light of the inside of the light guide plate to the upper side of the light guide plate. The light radiated from the second optical source or a third optical source(134) passes through the penetration part of the reflective layer. The third optical source is turned on with the second source when the first optical source is turned off. The third optical source reinforces the brightness of the second optical source.