A power supply/demand management device includes: a battery health acquisition controller configured or programmed to acquire a battery health X of the storage battery; a power selling amount management controller configured or programmed to acquire a desired power selling amount and correct desired power selling amount based on the battery health X acquired by the battery health acquisition controller; a power transmission/reception management controller configured or programmed to manage an amount of received/transmitted power between the storage battery and the power transmission/distribution system, based on the corrected power selling amount; and an incentive management controller configured or programmed to calculate an incentive to be provided to the user of the storage battery based on the corrected power selling amount.