Abstract: Method of obtaining terephthalic acid from waste polyethylene terephthalate by depolymerization with microwave heating of the reaction mixture, and its subsequent purification, wherein, after depolymerization, the mixture of products of the depolymerization reaction is mixed with water, a solid phase is separated from the formed mixture, the obtained solution is extracted with water-immiscible organic solvent and, after separation of phases, dissolved impurities are removed from the aqueous phase by its contact with a sorbent that is then separated, wherein, after separation of the sorbent, terephthalic acid is precipitated from the solution by its acidification and subsequently separated from the formed suspension.