A nitride read-only memory (NROM) device includes a comparator, a bias unit, a memory cell, a cycling cell, a compensation cell and a control unit. The comparator has a reference voltage. The bias unit is for outputting a bias voltage to the comparator, and the comparator outputs a bit value according to comparison of the bias voltage and the reference voltage. The memory cell is connected to the bias unit via a first switch. The cycling cell is connected to the bias unit via a second switch. The compensation cell is connected to the bias unit via a third switch. The control unit is for controlling the cycling cell and the compensation cell according to the bit value.