A solar mirror made up of a plurality of contiguous rectangular reflector panels. The panels are supported on their long sides by precambered sections. These sections are individually connected to spaced parallel extending members forming joists and comprise part of a rigid frame which includes a single bearing girder movably mounted with respect to a fixed base. Distance adjustment means are provided for moving the members perpendicular to the longitudinal axis of the girder and angular adjustment means are provided to rotate the members about the longitudinal axis.