A capacitor includes an electrode assembly, having at least one positive electrode, at least one negative electrode, and at least one dielectric or separator interposed between the positive electrode and the negative electrode, and a case for receiving the electrode assembly. The electrode assembly is configured such that the positive electrode, the negative electrode, and the dielectric or the separator are arranged in a horizontal direction, which is perpendicular to the thickness direction of the electrode assembly, and such that the positive electrode and the negative electrode have a complementary pattern.