A mounting plate includes a first fixing device for an electrical device and a second fixing device for a top-hat shaped mounting rail having a first offset support flange and a second offset support flange. The second fixing device includes a first holder and a second holder each having a contact portion and each being disposed mirror-symmetrically about a longitudinal axis of the mounting plate on a rear surface of the mounting plate. The second fixing device further includes an abutment opposite the first and second holders, and a metal projection configured to clamp at least one of the first and second offset support flanges against the contact portions of the first and second holders. The projection is configured to deform upon clamping of the at least one of the offset support flanges.