Provided are a capacitor and a method for manufacturing the capacitor, the capacitor including: a first thin-film electrode layer; a second thin-film electrode layer; a dielectric layer, including a binary metal oxide, between the first thin-film electrode layer and the second thin-film electrode layer; and an interlayer, including an anionized layer, between the dielectric layer and at least one of the first thin-film electrode layer or the second thin-film electrode layer. The interlayer has a same type of crystal structure as and a different composition from the dielectric layer, and the anionized layer includes at least one of a monovalent cation, a divalent cation, or a trivalent cation.