Abstract: The invention comprises a lead-through for electric cables and the like which is fire-proof, gas-proof, and liquid-proof at a predetermined temperature. The cables extend through an opening in a ceiling, floor and/or wall. Guide strips encircle at least one conductor or cable; and filling members, when required, are placed between the sides of the opening and guide strips. The filling members and the strips comprise a material having a relatively high coefficient of cubic expansion. A support member for the strips is arranged to abut a support edge formed in a frame structure. The support member affords a reinforcement against high pressure acting on the lead-through.