A device for attaching an object to a prefabricated wall of a building, this device: - being designed for being at least partially embedded within the material of the prefabricated wall and comprising: - at least two means (10; 10') for attaching the object to the prefabricated wall; - a means for positioning at least a first one of the means (10; 10') for attaching the object relative to at least a second one of the means (10': 10) for attaching this object, this means for positioning being formed of a support including at least one first means for receiving this first means for attaching this object and at least one second means for receiving this second means for attaching this object; - at least one means for placing the at least two means (10; 10') for attaching the object to the prefabricated wall, this at a determined distance from the head of the wall; - each of the means (121; 121') for receiving one of the means (10; 10') for attaching the object being formed of a cutout, which the support includes, the shape and/or the dimensions of which are defined for receiving one of the means (10; 10') for attaching; - wherein the shape and/or the dimensions are defined for tightly receiving one of the means for attaching. - being designed for being at least partially embedded within the material of the prefabricated wall and comprising: - at least two means (10; 10') for attaching the object to the prefabricated wall; - a means for positioning at least a first one of the means (10; 10') for attaching the object relative to at least a second one of the means (10': 10) for attaching this object, this means for positioning being formed of a support including at least one first means for receiving this first means for attaching this object and at least one second means for receiving this second means for attaching this object; - at least one means for placing the at least two means (10; 10') for attaching the object to the prefabricated wall, this at a determined distance from the head of the wall; - each of the means (121; 121') for receiving one of the means (10; 10') for attaching the object being formed of a cutout, which the support includes, the shape and/or the dimensions of which are defined for receiving one of the means (10; 10') for attaching; - wherein the shape and/or the dimensions are defined for tightly receiving one of the means for attaching. - at least two means (10; 10') for attaching the object to the prefabricated wall; - a means for positioning at least a first one of the means (10; 10') for attaching the object relative to at least a second one of the means (10': 10) for attaching this object, this means for positioning being formed of a support including at least one first means for receiving this first means for attaching this object and at least one second means for receiving this second means for attaching this object; - at least one means for placing the at least two means (10; 10') for attaching the object to the prefabricated wall, this at a determined distance from the head of the wall; - each of the means (121; 121') for receiving one of the means (10; 10') for attaching the object being formed of a cutout, which the support includes, the shape and/or the dimensions of which are defined for receiving one of the means (10; 10') for attaching; - wherein the shape and/or the dimensions are defined for tightly receiving one of the means for attaching.