Provided is a cobalt complex which is useful for the production of a cobalt-containing thin film under conditions where no oxidizing gas is used. A cobalt complex represented by general formula (1) (wherein R1 represents a silyloxy group represented by general formula (2) (wherein R6, R7 and R8 independently represent an alkyl group having 1 to 6 carbon atoms); R2 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a silyloxy group represented by general formula (2); R3, R4 and R5 independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; and L represents a diene having 4 to 10 carbon atoms) is used.