In the bulb socket 1 according to the invention, the connecting terminal 4 to be insert molded within the bulb insertion portion 2 includes the three surfaces, that is, the two side walls 5, 6 having a substantially L-like shape as a whole and the bottom wall 7. In one side wall 5, there are provided not only contact piece 8 and securing piece 9 which can be respectively contacted with the bulb wedge, but also the inflow preventive piece 11 which prevents the flowing-around molding material from flowing into the bulb storage portion 10 and also can strengthen the fixation of the connecting terminal 4 within the bulb insertion portion 2. Also, when molding the bulb socket 1, the fall preventive cores 20 to prevent the deformation of the side walls 5 and 6 are inserted into the bulb storage portion 10 and also into the peripheral portions of the bulb storage portion 10 and, at the same time, the leading end portion 11a of the inflow preventive piece 11 is insert molded within the bulb socket 1.