PURPOSE: To enhance the easiness of operation to secure part of a bulb such as a fluorescent lamp to a holder of a mounting member, provide fine adjustability for the relative location of the bulb and mounting structure, and prevent dislocation until regular fixation is made.

CONSTITUTION: A two-side adhesive tape 15 as an intermediate member is interposed and fixed provisionally between the joining surfaces of fixation parts which are to secure the ends 13a, 13b of a fluorescent lamp to lamp holders 14a, 14b. The gap between these joining surfaces of fixation parts formed by interposing of the intermediate member is filled with a Si adhesive 18, which is dried and solidified to generate regular fixation.