A power storage device includes a storage battery that stores electric power, a battery management unit that monitors and protects the storage battery, an inverter configured to convert DC power outputted from the storage battery into AC power and outputting the AC power, and convert externally supplied AC power into DC power and supplying the DC power to the storage battery, a liquid storage container that houses therein the storage battery, the battery management unit, and the inverter in a state where surroundings of the storage battery, the battery management unit, and the inverter are filled with a liquid, a temperature adjustment unit that performs heat transfer between the liquid and outside air to adjust a temperature of the liquid to a particular target temperature, and a heat insulating material arranged to surround the liquid storage container.