The first overtone vibration‐rotation lines of hydrogen fluoride have been observed around the wavelength region of 1.3 &mgr;m by using a current‐tunable InGaAsP semiconductor laser operated at the temperature range from −24 °C to +24 °C. The laser frequency has been locked to one of theR‐branch lines with the stability of 2.0×10−10≥&sgr;(2,&tgr;)≥7.9×10−11at the averaging time between 1 and 240 s.