Abstract: In an incandescent lamp unit, a base assembly of a rectangular section and which holds the pinched portion of the bulb comprises a first and second bases. The first base has formed therein a first opening in which said pinched portion can be introduced and first lug members extending from the edges of the first opening and which abut the upper portion of the pinched portion to limit the latter from moving longitudinally and laterally. On the other hand, the second base is so made as to be attached to the first base and has formed therein a second opening in which the pinched portion can be introduced, and it is also provided with second lug members extending obliquely and downwardly from the second opening and which abut the lower portion of the pinched portion to limit the latter from moving in the vertical plane.