The present disclosure relates to a monotonic counter whose value is represented by a number N of binary words of N memory cells of a non-volatile memory, and being able to implement a step increment operation wherein if only one first memory cell represents a first value different from zero, then a second value equal to the said first value incremented by two times the said step is written into a second memory cell of rank directly higher than the rank of the first memory cell; and if a third and a fourth memory cell of consecutive ranks represent, respectively, a third value and a fourth value different from zero, then the third value of the third memory cell of lower rank is erased.