A capacitive element using a liquid as a dielectric, whereby the capacitance is prevented from changing. The capacitive element is equipped with: a storage container that has an inlet port for introducing a liquid serving as a dielectric, has an outlet port for discharging the liquid, and is filled with the liquid; and at least one pair of electrodes that are provided in the storage container and face each other, wherein an opening section for exhausting air bubbles in the storage container is formed in an upper wall of the storage container.