Abstract: A cathode-ray tube socket substrate for use with a cathode-ray tube of a cathode-ray tube display unit such as a television receiving set comprising a cathode-ray tube socket mounted on an insulation substrate with its pin terminals securely connected to electrodes provided thereon. On the insulation substrate there are provided discharge electrodes in opposition to each other between the terminal electrodes and earth electrode, recesses for discharge gaps being provided between the discharge electrodes respectively, said recesses being covered by a sheathing member, the discharge means being integrally composed with compactness thereby enabling to miniaturize the whole socket substrate, stabilize the discharge action, and reduce the spark noises.