The invention relates to a switchgear cabinet or rack comprising a mounting unit, the front of which has vertical mounting sections that laterally delimit a cabinet frame for installed user-side units, said profiles having flat fixing sections that lie on a front mounting plane and that are used to fix laterally projecting mounting sections of the installed units, and comprising components of a detection device for determining the presence of an installed unit in an installation position of the cabinet frame. The components of the detection device have a vertical antenna strip that is attached to a mounting section and contains antenna elements arranged therein and code carriers that are designed as transponder elements and are provided on the installed units. In order to ensure the secure installation and reliable functioning of the detection device, each transponder element is attached to the mounting section of the associated installed unit that adjoins the antenna strip by means of a retaining element via a connecting section and the retaining element has a support section that adjoins the connecting section and projects outwards, parallel to the mounting plane. The transponder element is attached to the support section.