An electrical storage system includes an electrical storage device (10); a relay (SMR-B, SMR-G, SMR-P) switching between on/off states; a current interruption circuit (60) interrupting energization of the electrical storage device by causing the relay to switch from the on state to the off state; and a controller (30) executing drive control over the relay. The current interruption circuit includes an alarm circuit (63) outputting an alarm signal indicating overcharging/overdischarging of any one electrical storage block by comparing a voltage value of each electrical storage block with a threshold; a latch circuit (64) retaining the alarm signal; and a transistor (68) causing the relay to switch from the on state to the off state upon reception of an output signal of the latch circuit. The controller determines an energization state of the electrical storage device by executing control for turning on the relay while control for causing the alarm circuit to output the alarm signal is being executed.