PURPOSE: To efficiently remove borofluoride, fluoride ion, etc., in waste water by combining amino polyalcohol type chelate adsorbents with selective adsorbents of fluoride ions and adding them to the waste water.

CONSTITUTION: Amino polyalcohol type chelate adsorbents combined with selective adsorbents of fluoride ions are added to fluorine waste water containing borofluoride produced in a metal plating process, fluoroboric acid synthesis process, etc., to effect treatment of said waste water so that borofluoride ions, fluoride ions and borate ions coexisting with each other are simultaneously, efficiently removed. As an example of said amino polyalcohol type chelate resins, there is 'Amberite IRA-743(R)' chelate resin, etc., which selectively adsorbs borate ions. As an example of fluoride ion adsorbents, activated alumina adsorbent, etc., are available.