METHOD FOR OPERATING HYDROGEN PRODUCTION DEVICE AND METHOD FOR OPERATING A FUEL CELL SYSTEM

A hydrogen generator of the present invention comprises a reformer (1); a material gas supply passage (21) through which a material gas flows; a material gas supplier (5) which is provided at the material gas supply passage (21); a first valve (41) configured to open and close the material gas supply passage (21); an evaporator (2); a water supplier (6) configured to supply water to the evaporator (2); a communicating passage for allowing the reformer (1) to communicate with atmosphere; a second valve (42) configured to open and close the communicating passage; and a controller (10) configured to stop the material gas supplier (5) and the water supplier (6) and close the first valve (41) and the second valve (42) at shutdown; and open the second valve (42) prior to opening the first valve (41) when the material gas supplier (5) resumes supply of the material gas to the reformer (1).