Proposed is a filter module including a filter that filters impurities out in the coolant emitted from a cartridge which includes a housing and a cap. The filter module may include not only a filter accommodation member including a support surface and a perforating member protruding from the support surface but also a first sealing member with a first external diameter including a through-hole fitted into the perforating member. The first sealing member may be transformed into a shape with a second external diameter—the second external diameter is smaller than the first external diameter—corresponding to the width of an inlet of the housing in which the first sealing member accommodates a cap when the cap is perforated by the perforating member.