In a memory element with a first number of memory cells having a first retention time for holding a content of the memory cells and a second number of memory cells having a second retention time for holding the content of the memory cell, a method for refreshing the memory cells comprises a step of refreshing the first number of memory cells when reaching the first retention time and a step of refreshing the second number of memory cells when reaching the second retention time. An apparatus for refreshing the memory cells of the memory element is provided for refreshing the first number of memory cells when reaching the first retention time, and for refreshing the second number of memory cells when reaching the second retention time.