ILLUMINATING LAMP

Thermal energy generated by a plurality of light emitting diodes is efficiently diffused to the outside. An illuminating lamp is provided with an attaching substrate (4) whereupon a protection cover (3), which has a plurality of planarly fixed projectors (2) each having a light emitting diode as a light source and transmits light, is fixed on one plate face (4a) so as to cover the projectors; a plurality of board-like cooling fins (5) which protrude from the other plate face (4b) of the attaching substrate and are fixed so as to dissipate heat generated by the projector; and a housing (6) which has a storing concave part (6a) and has the attaching substrate fixed thereon. The attaching substrate is formed such that a space (S) for taking the external air is formed between the attaching substrate and the inner circumferential wall (6d) of the housing. The board-like cooling fins protrude above the space so as to be cooled by the external air taken from the space. The housing is provided with a plurality of slits (63) which discharge the external air, which is taken from the space and warmed by heat discharged from the board-like cooling fins, to the external.