The invention provides a semiconductor storage device which can restrain the uneven high voltage applied to the storage unit and can provide the high voltage with high precision. The semiconductor storage device includes a storage unit array, a Y decoder circuit, a X decoder circuit, a sense amplifier circuit, a Y gate circuit, a high voltage generating circuit, a high voltage regulator circuit, and a voltage adjusting circuit. The voltage modifying data for adjusting the potential of the anode of the zener diode so as to adjust the high voltage applied to the storage unit array is written into the storage unit array. The voltage modifying data is used to adjust voltage by the voltage adjusting circuit.