To provide a battery state monitor capable of detecting abnormality of a battery cell in a short time and capable of accurately performing detailed abnormality treatment.

The battery state monitor includes a comparison circuit 3 which compares magnitude relation between cell voltage and a threshold value of each of a plurality of battery cells 10, a voltage detection circuit 5 which detects voltage information of each of the plurality of battery cells 10, a micro computer 6 which monitors the state of the battery cell 10 based on the comparison result outputted from the comparison circuit 3 and the voltage information outputted from the voltage detection circuit 5, and a latch part 61 which holds the comparison result outputted to the micro computer 6 from the comparison circuit 3.