PURPOSE: To obtain a variable phase shift control circuit with wide control range and good linearity by providing an up-converter and a down-converter to a signal system, giving a delay time difference to a local signal system of both and controlling variably its local frequency.

CONSTITUTION: An output of a voltage controlled variable frequency oscillator 12 generating a local signal is inputted to the 1st frequency converting mixer 1a acting like the up-converter and the 2nd frequency converting mixer 1b acting like the down-converter connected in cascade to a signal system to be phase-shifted via delay lines 9, 10 having different delay time, then the amount of change in the phase is represented by the product between the frequency displacement of the logcal signal and the delay time difference of the two delay lines. Then, the frequency displacement of the local signal is decreased in selecting the latter larger, allowing to improve the linearity and to obtain a wide control range.