The invention relates to a gas/liquid separator comprising a capacitive level sensor, which is particularly suitable for systems that employ reduced volumes of fluids at high pressures. The inventive separator includes a metal part comprising a borehole which is closed at the lower end thereof, such as to form a container. The aforementioned container comprises at least one gas inlet, one liquid outlet and one gas outlet. A cooling system in the form of a Peltier cell that is in contact with the walls of the metal part, generates the condensation of the liquid which is collected at the bottom of the container until the introduction of a probe, which is electrically isolated from the system and which forms an electric condenser with the walls of the part. The capacity of the condenser varies according to the level of liquid in the container. In addition, a frequency signal is generated by means of an oscillator output signal that is proportional to the response from the sensor and, consequently, the height of the liquid in the container.