A hydrogen generation apparatus, comprising: a reformer configured to reform a raw material that contains hydrocarbon to generate a hydrogen-contain gas; a raw material supply device configured to supply the raw material to the reformer ; a combustor configured to combust at least one of the raw material and the hydrogen-containing gas to heat the reformer ; a water supply device configured to supply water to the reformer ; a reformer temperature detector configured to detect a temperature of the reformer ; an independent activation power supply which is a secondary power source independent to a first and primary power supply, the independent activation power supply configured to supply power to at least the raw material supply device and the water supply device ; and a controller configured to supply power to auxiliary machinery including the raw material supply device and the water supply device from at least the first power supply other than the independent activation power supply to activate the auxiliary machinery during typical activation, supply power to auxiliary machinery from only the independent activation power supply to activate the auxiliary machinery during special activation, in which power is not supplied from the first power supply, and characterized in that the controller configured to initiate water supply to the reformer when the temperature of the reformer becomes a first temperature during the special activation, and initiate water supply to the reformer when the temperature of the reformer becomes a second temperature higher than the first temperature during the typical activation, wherein the typical activation is an operation where power is being supplied from the first power supply, and the special activation is an operation where power is being supplied from only independent activation power supply . a reformer configured to reform a raw material that contains hydrocarbon to generate a hydrogen-contain gas; a raw material supply device configured to supply the raw material to the reformer ; a combustor configured to combust at least one of the raw material and the hydrogen-containing gas to heat the reformer ; a water supply device configured to supply water to the reformer ; a reformer temperature detector configured to detect a temperature of the reformer ; an independent activation power supply which is a secondary power source independent to a first and primary power supply, the independent activation power supply configured to supply power to at least the raw material supply device and the water supply device ; and a controller configured to supply power to auxiliary machinery including the raw material supply device and the water supply device from at least the first power supply other than the independent activation power supply to activate the auxiliary machinery during typical activation, supply power to auxiliary machinery from only the independent activation power supply to activate the auxiliary machinery during special activation, in which power is not supplied from the first power supply, and characterized in that the controller configured to initiate water supply to the reformer when the temperature of the reformer becomes a first temperature during the special activation, and initiate water supply to the reformer when the temperature of the reformer becomes a second temperature higher than the first temperature during the typical activation, wherein the typical activation is an operation where power is being supplied from the first power supply, and the special activation is an operation where power is being supplied from only independent activation power supply . <EOS>