The physically unclonable function device (DIS) comprises a set of MOS transistors (TR1i, TR2j) mounted in diodes having a random distribution of respective threshold voltages, and comprising N first transistors and at least one second transistor. At least one output node of the function is capable of delivering a signal, the level of which depends on the comparison between a current obtained using a current circulating in the at least one second transistor and a current obtained using a reference current that is equal or substantially equal to the average of the currents circulating in the N first transistors. A first means (FM1i) is configured to impose on each first transistor a respective fixed gate voltage regardless of the value of the current circulating in the first transistor, and a second means (SM2j) is configured to impose a respective fixed gate voltage on each second transistor regardless of the value of the current circulating in the second transistor.