Inspection device for inspecting an externally threaded element such as a screw, comprising an open-ended housing with an internal screw thread that is substantially cylindrical able to receive by screwing and to retain the said externally threaded element that is to be inspected and that has a predefined external screw thread, in which device - the inspection device comprises at least two jaws (3, 4, 28-30) extending between a proximal end (3a, 4a) and a distal end (3b, 4b) and each comprising an angular portion (3c, 4c, 28c-30c) of internal cylindrical threaded die cavity the interior screw threading parameters of which are aligned to the screw threading parameters of the said predefined external screw thread, - the said angular portions (3c, 4c, 28c-30c) of cylindrical threaded die cavity are formed on a respective working face (3d, 4d, 28d-30d) of the jaws (3, 4, 28-30), extend between the respective proximal (3a, 4a) and distal (3b, 4b) ends of the jaws (3, 4, 28-30) and open onto a respective proximal face (3e, 4e) of the jaws (3, 4, 28-30), - the jaws (3, 4, 28-30) can be moved between a closed position and an open position, - in the closed position, the jaws (3, 4, 28-30) are arranged in such a way as to form between them, because of the complementary nature of their respective angular portions (3c, 4c, 28c-30c) of threaded die cavity, the said substantially cylindrical internally threaded open-ended housing, - in the open position, the jaws (3, 4, 28-30) are arranged in such a way as to allow a cylindrical element having an outside diameter equal to that of the said predefined external screw thread to be introduced in a simple translational movement between their respective angular portions (3c, 4c, 28c-30c) of threaded die cavity, characterized in that the inspection device comprises sensor means configured to supply closure information when the jaws (3, 4, 28-30) are in the closed position. - the inspection device comprises at least two jaws (3, 4, 28-30) extending between a proximal end (3a, 4a) and a distal end (3b, 4b) and each comprising an angular portion (3c, 4c, 28c-30c) of internal cylindrical threaded die cavity the interior screw threading parameters of which are aligned to the screw threading parameters of the said predefined external screw thread, - the said angular portions (3c, 4c, 28c-30c) of cylindrical threaded die cavity are formed on a respective working face (3d, 4d, 28d-30d) of the jaws (3, 4, 28-30), extend between the respective proximal (3a, 4a) and distal (3b, 4b) ends of the jaws (3, 4, 28-30) and open onto a respective proximal face (3e, 4e) of the jaws (3, 4, 28-30), - the jaws (3, 4, 28-30) can be moved between a closed position and an open position, - in the closed position, the jaws (3, 4, 28-30) are arranged in such a way as to form between them, because of the complementary nature of their respective angular portions (3c, 4c, 28c-30c) of threaded die cavity, the said substantially cylindrical internally threaded open-ended housing, - in the open position, the jaws (3, 4, 28-30) are arranged in such a way as to allow a cylindrical element having an outside diameter equal to that of the said predefined external screw thread to be introduced in a simple translational movement between their respective angular portions (3c, 4c, 28c-30c) of threaded die cavity,