A housing part for an explosion-protected housing (10) with flameproof encapsulation. The housing part comprises a porous body (20) in a passage (15) of the housing part. The passage (15) is closed in a flameproof manner by means of the porous body (20). The porous body (20) comprises an inner side (21) assigned to the interior of the housing (10) and an outer side (22) assigned to the surrounding area (12) comprising the explosive atmosphere. A gas volume flow can pass through the porous body (20), entering the porous body (20) on the inner side (21) and escape on the outer side (22) or vice versa. To prevent the penetration of water or of other aqueous liquids into the interior of the housing (10), the porous body (20) comprises a hydrophobic surface (B) in at least one area (31).