Abstract: An apparatus for automatically measuring the vertical profile of the temperature in the atmosphere.The temperature of the air is obtained by the measurement of the propagation speed of sound wave pulses, to which it is directly related, by means of a continuous Doppler radar.The automation of the measurement is ensured by the automatic control of the radar emission frequency by the Doppler frequency which it receives, with reference to the frequency of the sonic emitter oscillator.The apparatus presents a major advantage with respect to known methods in use for measurements of the lower layers of the atmosphere such as the meteorological towers and the sounding balloons due to its automatic functioning.