PURPOSE: To easily open or close a light shielding plate and improve the workability on lamp replacement and the like by forming a socket fitting section fitting lamp sockets to a support arm fitted to the lower face of an apparatus main body and a fitting section of the light shielding plate.

CONSTITUTION: Electric parts 16, 17 forming a lighting circuit are fitted to an apparatus main body 11 in a line type indirect illumination apparatus installed on the ceiling face in an electric car, for example, and a socket fitting section 28 fitting lamp sockets 30, 31 to a support arm 22 fitted on the lower face of the apparatus main body 11 and a fitting section 33 of a light shielding plate 40 are formed. The light of a lamp 29 is radiated from between the ceiling face and the light shielding plate 40, and indirect illumination is obtained. The light shielding plate 40 can be made lightweight and is easily opened or closed, and the workability on the replacement, inspection and repair of the lamp 29 is improved.