A hydrogen sensor device (100, 200) for measuring a concentration of dissolved hydrogen gas in liquid, the hydrogen sensor device (100, 200) comprising: a sensor unit measuring a concentration of hydrogen gas; and a housing coupled to the sensor unit and including a housing body having an opening portion formed in at least a part thereof and a gas separation film coupled to the opening portion to be gaseously and liquidly sealed, wherein a sealing space isolated from the liquid and external air is formed in the housing by the housing body and the gas separation film, and the gas separation film adapted for letting the dissolved hydrogen gas in the liquid into the sealing space, a pumping unit pumping oxygen in the sealing space to the outside to remove the oxygen, the pumping unit is coupled to the housing, the pumping unit is integrally formed with the sensor unit, the sensor unit includes a hetero-assembly of an oxygen ion conductor and a hydrogen ion conductor, the hydrogen ion conductor attached to at least a part of the oxygen ion conductor exposed to the sealing space side, a sensing electrode formed on the surface of the hydrogen ion conductor exposed to the sealing space, a reference electrode formed on the surface of the oxygen ion conductor at the external air side, the reference electrode is in communication with the external air or is covered with a reference substance that fixes oxygen partial pressure at the reference electrode side, and a heater substrate spaced apart from the oxygen ion conductor with a predetermined interval by a spacer, the spaced interval being provided to be in communication with the external air, an electromotive force measuring unit configured for measuring an electromotive force between the reference electrode and the sensing electrode, the pumping unit includes a first pumping electrode formed on the surface of the sealing space side which is not attached to the hydrogen ion conductor of the oxygen ion conductor, a second pumping electrode formed on the surface of the oxygen ion conductor at the external air side, and a pumping power supply configured for applying voltage or current between the first pumping electrode and the second pumping electrode, and the sensor unit is configured such that, as the concentration of the dissolved hydrogen gas is changed, the electromotive force is changed, and the voltage or current is applied between the first pumping electrode and the second pumping electrode by the pumping power supply to pump the oxygen at the sealing space side to the external air side. a sensor unit measuring a concentration of hydrogen gas; and a housing coupled to the sensor unit and including a housing body having an opening portion formed in at least a part thereof and a gas separation film coupled to the opening portion to be gaseously and liquidly sealed, wherein a sealing space isolated from the liquid and external air is formed in the housing by the housing body and the gas separation film, and the gas separation film adapted for letting the dissolved hydrogen gas in the liquid into the sealing space, a pumping unit pumping oxygen in the sealing space to the outside to remove the oxygen, the pumping unit is coupled to the housing, the pumping unit is integrally formed with the sensor unit, the sensor unit includes a hetero-assembly of an oxygen ion conductor and a hydrogen ion conductor, the hydrogen ion conductor attached to at least a part of the oxygen ion conductor exposed to the sealing space side, a sensing electrode formed on the surface of the hydrogen ion conductor exposed to the sealing space, a reference electrode formed on the surface of the oxygen ion conductor at the external air side, the reference electrode is in communication with the external air or is covered with a reference substance that fixes oxygen partial pressure at the reference electrode side, and a heater substrate spaced apart from the oxygen ion conductor with a predetermined interval by a spacer, the spaced interval being provided to be in communication with the external air, an electromotive force measuring unit configured for measuring an electromotive force between the reference electrode and the sensing electrode, the pumping unit includes a first pumping electrode formed on the surface of the sealing space side which is not attached to the hydrogen ion conductor of the oxygen ion conductor, a second pumping electrode formed on the surface of the oxygen ion conductor at the external air side, and a pumping power supply configured for applying voltage or current between the first pumping electrode and the second pumping electrode, and the sensor unit is configured such that, as the concentration of the dissolved hydrogen gas is changed, the electromotive force is changed, and the voltage or current is applied between the first pumping electrode and the second pumping electrode by the pumping power supply to pump the oxygen at the sealing space side to the external air side.