A hydrogen supply system includes an electrochemical hydrogen pump which includes: an electrolyte membrane; an anode provided on a first surface of the electrolyte membrane; a cathode provided on a second surface of the electrolyte membrane opposite to the first surface; and a current adjuster adjusting a current amount flowing between the anode and the cathode, and which performs a hydrogen supply operation by allowing a current to flow between the anode and the cathode using the current adjuster so as to boost the pressure of hydrogen which is supplied to an anode side at a cathode side and to supply the pressure-boosted hydrogen to a hydrogen demander; and a dew point adjuster adjusting a dew point of a mixed gas in which a hydrogen-containing gas which is discharged from the anode side and a hydrogen-containing gas which is supplied from an outside are mixed together.