A hydrogen system includes: a generator which generates hydrogen-containing gas; a storage which stores the hydrogen-containing gas generated by the generator; a first gas passage which connects the generator and the storage; a housing which houses the generator, the storage and the first gas passage; a second gas passage in which the hydrogen-containing gas discharged from the first gas passage to an outside of the housing flows; a first valve provided to the second gas passage; a third gas passage in which the hydrogen-containing gas discharged from the storage to the outside of the housing flows; a second valve provided to the third gas passage; and a controller which opens at least one of the first valve and the second valve.