An interior illumination lamp 10 including a design portion 20 in which a lens 54 is fixed to a bezel 22 of a housing 21 capable of being attached to an opening 13a provided at an interior member 13 of a vehicle 11, a functional portion 30 arranged to a rear side of the interior member 13 by being supported by the design portion 20 and having a light source 37, and a guide portion 26 in a groove-like shape provided for guiding an electric wire W/H connected to the functional portion 30, in which a clip 25 is arranged to a notched portion 26b provided at a wall portion 26a of the guide portion 26 and front ends of the wall portion 26a interposing the notched portions 26b are connected to ride over the notched portions 26b. That is, upper portions of the notched portions 26b of the clips 25 provided at the guide portion 26 are connected and therefore, the electric wire W/H wired along the guide portion 26 can be prevented from extruding from the notched portion 26b to be bit thereby Further, erroneous wiring can be prevented by wiring an electric wire along the guide portion 26.