Abstract: The invention relates to separating different substances, more concretely, to a method and apparatus for filters, degassing, dehydrating and removing products of ageing in insulating and other petroleum oils. The technical result is that the aforesaid phases of processing oil or a mixture of oils are ensured with high efficiency for a single passage through an active component, and also the possibility of regenerating the adsorbents being used is ensured during the process of operation of the equipment, with simultaneous simplification of the construction and reduction of size and of power consumption. The apparatus 1 for filtering, degassing, dehydrating and removing products of ageing comprises at least one tank 2, in which are disposed cylindrical partitions 3, 4 filled with an adsorbent 5 and secured in the tank 2 by means of fixing elements 6. Partitions 3, 4 form channels for the passage of oil being processed.