Device for monitoring the temperature and tightness of a screw, said screw comprising at least a head and a shank and being intended to clamp one or more electrical conductors, said device comprising: - a temperature detector positioned near the screw head in order to measure the temperature of the screw, - a screw tightness detector comprising a sensor device and a first detection unit connected to the sensor device and designed to determine a level of tightness of the screw as a function of the detection status of the sensor device, - a signalling unit connected to an output of the first detection unit and designed to signal a screw tightness status supplied by the first detection unit and/or a temperature status supplied by a second detection unit, - a main housing in which the first detection unit is housed, the temperature detector being fixed to said main housing, said device being characterized in that: - said sensor device comprises a first part positioned on the head of the screw so as to rotate as one with said screw, and a second part, that is fixed with respect to the first part and designed to generate a detection status indicative of a position of the first part with respect to the second part; - the temperature detector comprises a component of the thermistor type connected to said second detection unit; - said signalling unit is connected to an output of the second detection unit; - the main housing also houses the second detection unit and said signalling unit; - the device further comprises a secondary housing through which there is formed an opening to allow the screw head to pass, this secondary housing bearing the second part of the sensor device of the screw tightness detector, said secondary housing being mounted on a hinge mechanism produced on the main housing so as to be able to pivot with respect thereto. - a temperature detector positioned near the screw head in order to measure the temperature of the screw, - a screw tightness detector comprising a sensor device and a first detection unit connected to the sensor device and designed to determine a level of tightness of the screw as a function of the detection status of the sensor device, - a signalling unit connected to an output of the first detection unit and designed to signal a screw tightness status supplied by the first detection unit and/or a temperature status supplied by a second detection unit, - a main housing in which the first detection unit is housed, - said sensor device comprises a first part positioned on the head of the screw so as to rotate as one with said screw, and a second part, that is fixed with respect to the first part and designed to generate a detection status indicative of a position of the first part with respect to the second part; - the temperature detector comprises a component of the thermistor type connected to said second detection unit; - said signalling unit is connected to an output of the second detection unit; - the main housing also houses the second detection unit and said signalling unit; - the device further comprises a secondary housing through which there is formed an opening to allow the screw head to pass, this secondary housing bearing the second part of the sensor device of the screw tightness detector, said secondary housing being mounted on a hinge mechanism produced on the main housing so as to be able to pivot with respect thereto.