A device for concentrating solar radiation (4) with longitudinal mirrors (7) and a longitudinal receiver (1), has mirrors with a circular cross-section with a radius of curvature that is twice the transverse distance from the center (35) of each mirror to the central point (3) of the receiver. The width of the receiver is 1% of the transverse distance from the central point to the center (89) of the furthest mirror (32). The width of each mirror is determined according to the drift of the rays reflected when the mirror focuses the sun, prescribing an equal width for all mirrors, which is: equal to the width of the active face (2) of the receiver when mounted according to the meridian; and triple the width of the active face (2) of the receiver when mounted according to the parallel of latitude. The mirrors are installed in a contiguous manner and the receiver is installed at a height on columns (8).