A process for manufacturing prefabricated infill panels of the "thermal break" type for the building industry in a formwork (24), comprising a step of forming a borne layer (10) by way of casting concrete in the formwork provided with a reinforcement (28) on the bottom, laying thermal insulating strips (16A) above the casting and against its respective wall of the formwork (24), arranging connection means (18) partially buried and partially projecting from the borne layer (10) for anchoring to a bearing layer (12), positioning thermal insulating slabs (16B) to cover an upper surface of the borne layer (10), arranging lightening blocks (15), if any, casting concrete for obtaining the bearing layer (12) provided with a respective reinforcement net and irons, vibrating the concrete and, finally, taking the panel out of the formwork (24).
