To provide a lamp fixture dedicated to LEDs capable of installing an LED lamp without being affected by the case shape of the LED lamp and having a function of preventing breakage due to overheat without lighting, or immediately turning off, an incandescent lamp even if it is installed by mistake.

As for a lamp fixture having an LED lamp installed, a current interruption element of self-recovery type having a positive temperature coefficient for cutting off electric current when a predetermined temperature is exceeded is arranged so as to be thermally jointed to the lamp fixture. Even if an incandescent lamp is erroneously installed and lit, it senses the heat generated by the filament of the incandescent lamp and the current interruption element is operated to turn off the incandescent lamp.