NOVELTY - Apparatus (1) for generating hydrogen, preferably hydrogen rich fuel gas using source gas, comprises: (a) source gas flow path (2); (b) source gas cutoff valve (3) provided in source gas flow path; (c) fuel gas flow channel (6); (d) fuel gas cutoff valve which flows through or blocks the fuel gas; (e) gas-leakage detection means (12) which is provided downstream from the fuel gas cutoff valve, and detects a gas leakage; and (f) control part (14) which controls opening and closing of the valve of the source gas cutoff valve and the fuel gas cutoff valve is provided.    USE - The apparatus is useful for generating hydrogen (claimed).    ADVANTAGE - When the internal pressure of hydrogen generating apparatus is declining, the gas leakage to downstream flow path can be detected from hydrogen generating apparatus.    DETAILED DESCRIPTION - Apparatus for generating hydrogen, preferably hydrogen rich fuel gas using source gas, comprises: (a) source gas flow path which supplies source gas to the hydrogen generation device from a material supply source; (b) source gas cutoff valve provided in source gas flow path; (c) fuel gas flow channel which emits the fuel gas from hydrogen generation device; (d) fuel gas cutoff valve which flows through or blocks the fuel gas which was provided in the fuel gas flow channel, and was discharged from the hydrogen generation device; (e) gas-leakage detection means which is provided downstream from the fuel gas cutoff valve, and detects a gas leakage; and (f) control part which controls opening and closing of the valve of the source gas cutoff valve and the fuel gas cutoff valve is provided, where at the time of shutdown of the hydrogen generation device, the control part blocked the source gas cutoff valve and the fuel gas cutoff valve, then release and the fuel gas cutoff valve are closed for the source gas cutoff valve, and gas leakage is detected by the gas leakage detection means.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of the hydrogen generating apparatus.    Hydrogen generation apparatus (1)    Source gas flow path (2)    Source gas cutoff valve (3)    Water vapor flow path (4)    Water vapor cutoff valve (5)    Fuel gas flow channel (6)    Fuel gas cutoff valve (7)    Burner (8)    Combustion gas flow path (9)    Combustion gas cutoff valve (10)    Temperature sensor (11)    Leak detector (12)    Air blower (13)    Control part (14)