Abstract: The invention relates to a mirror comprising a glass sheet and a silver layer applied to the glass and provided on its back with a protective coating comprising a layer of dried and crosslinked paint of the alkyd type and a layer of dried and crosslinked paint of the polyurethane type, the alkyd layer being located between the silver layer and the polyurethane layer. The invention also relates to its use for deflecting solar light onto a heat collector. The invention also relates to a process for manufacturing a mirror comprising: a silver layer is deposited on a glass sheet using a silverplating solution; then a layer of alkyd paint having a viscosity of between 25 and 110 seconds measured using a Ford No. 4 cup is applied on the side with the silver layer; then the alkyd paint layer is dried and crosslinked; then a layer of polyurethane paint having a viscosity of between 25 and 110 seconds measured using a Ford No.