Method for diagnosing the state of wear of an electrical switching unit connected to a coil for actuating contacts of said electrical unit, the method comprising a phase of checking of said electrical unit, - said checking phase using: - learning data (CD1, CD2, CD3, CD4, CD5, CRU) loaded previously and corresponding to a type of product representative of said electrical unit, and - initialization data corresponding to said unit to be controlled and stored in an initialization phase, and - said checking phase comprising: - the reception of a measurement signal representative of an electrical quantity of said coil and the acquisition of a measurement curve on the opening of said electrical unit, said measurement curve representing said signal as a function of time, - the determination (30, 31, 51) of values of local descriptors (DL1, DL2, DL3, DL4, DL5) of said measurement curve as a function of values of said measurement curve, of stored initialization data, and of first loaded learning data, - the determination of the positioning of the values of local descriptors (DL1, DL2, DL3, DL4, DL5) of the measurement curve with respect to second learning data (CD1, CD2, CD3, CD4, CD5), representative of trend curves (CD1, CD2, CD3, CD4, CD5) of descriptors representative of predefined characteristics of said electrical signal during the life of said electrical unit, and - the determination (32, 53-55) of an overall state class as a function of said values of positionings of local descriptor values (DL1, DL2, DL3, DL4, DL5) and of the measurement curve with respect to said second learning data (CD1, CD2, CD3, CD4, CD5). - said checking phase using: - learning data (CD1, CD2, CD3, CD4, CD5, CRU) loaded previously and corresponding to a type of product representative of said electrical unit, and - initialization data corresponding to said unit to be controlled and stored in an initialization phase, and - learning data (CD1, CD2, CD3, CD4, CD5, CRU) loaded previously and corresponding to a type of product representative of said electrical unit, and - initialization data corresponding to said unit to be controlled and stored in an initialization phase, and - said checking phase comprising: - the reception of a measurement signal representative of an electrical quantity of said coil and the acquisition of a measurement curve on the opening of said electrical unit, said measurement curve representing said signal as a function of time, - the determination (30, 31, 51) of values of local descriptors (DL1, DL2, DL3, DL4, DL5) of said measurement curve as a function of values of said measurement curve, of stored initialization data, and of first loaded learning data, - the determination of the positioning of the values of local descriptors (DL1, DL2, DL3, DL4, DL5) of the measurement curve with respect to second learning data (CD1, CD2, CD3, CD4, CD5), representative of trend curves (CD1, CD2, CD3, CD4, CD5) of descriptors representative of predefined characteristics of said electrical signal during the life of said electrical unit, and - the determination (32, 53-55) of an overall state class as a function of said values of positionings of local descriptor values (DL1, DL2, DL3, DL4, DL5) and of the measurement curve with respect to said second learning data (CD1, CD2, CD3, CD4, CD5). - the reception of a measurement signal representative of an electrical quantity of said coil and the acquisition of a measurement curve on the opening of said electrical unit, said measurement curve representing said signal as a function of time, - the determination (30, 31, 51) of values of local descriptors (DL1, DL2, DL3, DL4, DL5) of said measurement curve as a function of values of said measurement curve, of stored initialization data, and of first loaded learning data, - the determination of the positioning of the values of local descriptors (DL1, DL2, DL3, DL4, DL5) of the measurement curve with respect to second learning data (CD1, CD2, CD3, CD4, CD5), representative of trend curves (CD1, CD2, CD3, CD4, CD5) of descriptors representative of predefined characteristics of said electrical signal during the life of said electrical unit, and - the determination (32, 53-55) of an overall state class as a function of said values of positionings of local descriptor values (DL1, DL2, DL3, DL4, DL5) and of the measurement curve with respect to said second learning data (CD1, CD2, CD3, CD4, CD5).