A hydrogen generation apparatus (100) includes: a reformer (10) configured to generate a hydrogen-containing gas by using a raw material and steam; a raw material passage (21) through which the raw material that is supplied to the reformer (10) flows; a hydrodesulfurizer (13) provided downstream from a most downstream valve (11) on the raw material passage (21) and configured to remove a sulfur compound from the raw material; a sealer (15) provided on a passage (24) downstream from the reformer (10) and configured to block communication between the reformer (10) and the atmosphere; and a depressurizer (16) provided on the raw material passage (21) at a portion connecting the hydrodesulfurizer (13) and the reformer (10) and configured to release, to the atmosphere, pressure in the reformer (10) that has increased after the sealer (15) is closed.