A method for manufacturing a concentrating photovoltaic solar sub-module equipped with a reflective face having a concave predefined geometric shape, wherein it includes laminating, in a single step, a multi-layer assembly comprising in succession: a structural element equipped with a reflective first face and a second face, opposite the first; a layer of a material of good thermal conductivity, higher than that of the material from which the structural element is composed, the layer being placed on the second face of the structural element; a layer of encapsulant or of adhesive; a photovoltaic receiver, the layer of encapsulant or of adhesive being placed between the layer of a material of good thermal conductivity and the receiver; a layer made of transparent encapsulating material, covering at least the entire surface of the photovoltaic receiver; and a transparent protective layer covering the layer made of transparent encapsulating material; and during the lamination, the reflective face of the structural element is shaped by being brought into contact with a convex surface of a counter-mold, in order to obtain the reflective face of concave predefined geometric shape.