a compound showing light emission from the triplet excited state wherein an energy difference between the vacuum level and the lowest unoccupied orbital level in the ground state calculated by a computational chemical means is 1 3 ev or more or an energy difference between the vacuum level and the lowest unoccupied orbital level in the ground state experimentally measured is 2 2 ev or more in the polymer compound and either the following or the following or both of them are satisfied energy in the ground state of the polymer compound energy in the lowest excited triplet state of the polymer compound energy in the ground state of the compound and energy in the lowest excited triplet state of the compound satisfy the relation et a u2212 es a0 gt et b u2212 es b0 the ratio pl a pl b of photoluminescence intensity of the polymer compound to photoluminescence intensity of the compound showing light emission from the triplet excited state is 0 8 or less application_number US 57135204 A description specifically regarding the iridium complex a and the polymer compound 1 1 the structure was optimized by a hatree fock hf method in this procedure lanl2dz was used for iridium contained in the iridium complex a and 6 31g was used for other atoms in the iridium complex a and the polymer compound 1 1 as.