NOVELTY - The solar thermal collector has at least one support frame (11) act to endure a solar energy absorber (13), one layer of thermal insulation material (19) containing at least one gelatinous substance of low thermal conductivity, and double-glazing glasses (12 and 12a). The material has felt and/or cotton consistency. The gelatinous substance contains a gaseous component instead of a liquid one. The substance is aerogel. The thermal insulation layer has a thickness ranging between about 4 mm and 12 mm and is set inside the support frame and below the solar energy absorbers.    USE - Solar thermal collector/solar panel for solar thermal plant.    ADVANTAGE - The insulation material can resist high temperatures without any particular damage, and thus the insulation material can be placed very close to the plate with no particular risks. The solar panel thickness is greatly reduced in overall dimensions. The solar panel gives the possibility of architectonic integration in buildings' vertical walls and among sloped roofs tiles, or to be inserted in balcony parapet, determining small environmental impact. The insulation material offers features of easy storage and transports by coils. The panel's production is simplified and is transported easily, and consequently reducing the costs. The efficiency loss is recovered by the adoption of double glazing, by reducing reduce the heat losses. The transmittance fall due to double glazing is then recovered by the high glasses transmittance. The double glazing is employed in their extraclear variant and endowed with an antireflective film ensuring very high transmittance factors, over 95%. The solar energy absorbers are coated with titanium oxide, chrome nitride or varnish, to increase the panel's capacity and thermal efficiency.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of solar panel.    Support frame (11)    Double-glazing glasses (12, 12a)    Solar energy absorber (13)    Layer of thermal insulation material (19)    Glass cover (20)