STORAGE SYSTEM AND PROTECTION METHOD

A storage system of an embodiment has a power supply circuit, a backup circuit and a protection circuit. The power supply circuit supplies power to a semiconductor storage element. The backup circuit has a condenser capable of being charged by using the power from the power supply circuit and supplies the power charged on the condenser to the semiconductor storage element when a voltage of the power supply circuit declines to be equal to or smaller than a threshold value set in advance. The protection circuit monitors a value of a leakage current of the condenser and performs an operation related to deterioration of the condenser when the value of the leakage current fulfills a deterioration condition set in advance.