The present invention provides anti-CEACAM1 antibodies with improved binding abilities specific to CEACAM1, and a use thereof. Anti-CEACAM1 antibodies according to the present invention exhibit superior binding abilities specific to CEACAM1, and also activate the anti-cancer immune functions of cytotoxic T cells and natural killer cells, and thus, each one of them can be effectively used as an anti-cancer agent and a composition for treating cancer.