A capacitor is a passive device on a circuit board that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. This is a list of known capacitor manufacturers, their headquarters country of origin, and year founded. The oldest capacitor companies. • - United States - founded in 1972. • - United States• - Germany• (ECC) - Japan• - Japan - founded in 1937. • - United States - founded in 1919.• - Japan - founded in 1940. • - United States - Dubilier founded in 1920. • General Atomics Electromagnetic Systems (GA-EMS) - United States • - Japan • - China• - Japan - founded in 1944.