An object of the invention is to provide a capacitor device that can be made slimmer and lighter and that enables the strength and heat dissipation properties to be improved. A capacitor device (1) has a plurality of capacitor units (2) integrally housed within a housing case (3), the housing case (3) having cylindrical housing sections (5) for housing the capacitor bodies. The housing sections (5) are longitudinally aligned in the same direction and are joined together as an integrated whole. A capacitor unit (2) is inserted via an opening (9) at one end of each of the housing sections (5) so that the entire circumference of the capacitor unit (2) is covered by the corresponding housing section (5). The housing sections (5) have a uniform thickness at least on the outer side along the outer periphery of the capacitor units.