A solar receiver, particularly of the type for parabolic linear solar concentrators comprising a receiver tube, for the circulation of a heat transfer fluid, which is supported in a longitudinally adaptable manner in a shell that comprises a shielding body provided with a longitudinal slit, and at least one lens for closing the slit, which is permeable to the solar radiation that during use is reflected toward the receiver tube by a concentrator mirror, with which the shell is associated during use. Between the receiver tube and the shell an annular chamber is provided, which contains a preselected thermally insulating gas, at an operating pressure substantially comprised between 1 mbar and 31 mbar, the preselected gas having a thermal conductivity of substantially less than 0.01 W/mK at the operating temperature at the operating pressure.