The disclosure relates to optical arrangements in a microlithographic projection exposure apparatus. In accordance with one aspect, an optical arrangement has at least one mirror segment arrangement including a plurality of separate mirror segments. The mirror segments are connected to a carrying structure of the projection exposure apparatus via mounting elements. At least one of the mounting elements, which is assigned to a first one of the mirror segments, extends, on the opposite side to the optically active surface of the mirror segment arrangement, at least partly into the region of a second mirror segment of the mirror segment arrangement. The second mirror segment is adjacent to the first mirror segment.