To facilitate the manufacture of a filter body of a by-pass element, to decrease a connection member of a filter body of a full flow element thereto and to simplify the connection work in a cartridge type combination type filter for oil treatment for filtering lubricating oil in an internal combustion engine.

The combination type filter for oil treatment is formed by using the filter body, which is obtained by forming a block like filter media having a through hole and a liquid retaining hole by integral molding, for the filter body of the by-pass element, connecting the filter body to a filtration oil introducing pipe body communicated with the through hole and the liquid retaining hole and having an inside pipe and an outside pipe and connecting to the filter body of the full flow element using the structural member.