An additive for a light-emitting layer contains a compound represented by formula (1): where X is P, C, or S; A is a cyclic hydrocarbon group that may have H, a direct bond, a chain hydrocarbon group, or a heteroatom; R is H or an alkyl group, and a plurality of R may link together to form a ring, and if said ring is formed, at least one R is an alkyl group; m is 0 or 1; r is 1 when X is a phosphorous atom or a carbon atom and 2 when X is a sulfur atom; n is a number represented by 3-m when X is a phosphorous atom, and a number represented by 2-m if X is a carbon atom or a sulfur atom; and p is 1 when m is 0, at least 1 when m is 1, and is a substitutable number in A.