A vacuum solar thermal panel including a vacuum envelope defining a sealed volume and able to withstand atmospheric pressure when evacuated, at least one heat absorber being disposed inside the vacuum envelope, a pipe entering and exiting the envelope and being in contact with the heat absorber, the vacuum envelope including a first plate made of glass, a peripheral frame, a metallic peripheral belt being joined to the first plate by way of a vacuum tight bulk glass-metal seal, including glass material and obtained by fusion and subsequent solidification. The metallic peripheral belt includes at least one elastically deformable portion that prevents the bulk glass-metal seal from getting damaged and is no more vacuum tight when subject to the evacuation process of the envelope and the thermal treatments of the panel and the potential reciprocal displacements of the glass plate and the joined metallic peripheral belt.