After retirement, Kamata became a manager for Furukawa Electric as Saburo Kawabuchi successor in 1976 and managed until 1978. The club won the champions in 1976 Japan Soccer League, 1976 Emperor's Cup and 1977 JSL Cup. In 1981, he signed with Japanese Regional Leagues club Daikyo Oil (later "Cosmo Oil"). He led the club to won league champions 4 times and promoted the club to Japan Soccer League Division 2 in 1986. He resigned in 1991. In 2007, he was selected Japan Football Hall of Fame.