Abstract: The invention relates to a phase comparator making it possible to measure the phase displacement between several very high stability oscillators and having for this purpose a system of pairs of measuring cascades each being connected to an oscillator and supplying a first and a second signal. It also comprises a multiplexer, a counting circuit, a computer and a computer coupler making it possible to compare the first signals in pairs in order to obtain a measuring range in which is located the phase displacement between two given oscillators and making it possible to compare the two signals, in order to obtain the displacement measurements in said range.