A hydrogen generation apparatus according to the present invention includes: a first desulfurizer (1); a second desulfurizer (2); a reformer (3) configured to generate a hydrogen-containing reformed gas from a raw material gas from which sulfur has been removed by at least one of the first desulfurizer (1) and the second desulfurizer (2); and a recycle passage (6) through which a part of the reformed gas generated by the reformer (3) is mixed into the raw material gas that is to be supplied to the second desulfurizer (2). The hydrogen generation apparatus is configured such that after installation or maintenance of the hydrogen generation apparatus, the raw material gas is supplied to the reformer (3) through the first desulfurizer (1) until a catalyst in the second desulfurizer (2) is activated by a mixed gas of the reformed gas supplied through the recycle passage (6) and the raw material gas, and after the catalyst in the second desulfurizer (2) is activated, the raw material gas is supplied to the reformer (3) through the second desulfurizer (2).