To provide a lamp fixture enabling to mount a lamp at an accurate position and temporarily lock a lamp holder into a socket.

The lamp fixture 10 comprises the lamp holder 30 to be externally fitted to an electrode portion at one end of the lamp 50, and the socket 20 having a fitting portion 22 into which the lamp holder 30 is inserted. The lamp holder 30 has a tapered portion 31b narrower frontward in the direction of insertion into the fitting portion 22, and a front end portion 31a formed at a constant width, and an annular locking groove 35 is formed in the front end portion 31a. In the fitting portion 22 of the socket 20 into which the lamp holder 30 is inserted, a tapered portion 22b and a front end insertion portion 22a are formed corresponding to the outside shape of a swollen portion 31 of the lamp holder 30. A lock body 26b is elastically protruded from the inner wall of the front end insertion portion 22a so as to be locked into the locking groove 35.