To more accurately detect abnormality at each part of a power supply device equipped with a storage means.

An auxiliary power supply device 102 comprises an electric double layer capacitor 44 which is the storage means, and the electric double layer capacitor 44 is charged by a charging circuit 42. A control part 120, in charging, compares the relationship between the inter-terminal voltage of the electric double layer capacitor 44 which is detected by an inter-terminal voltage detecting circuit 45 and a charging time at detection, to the relationship between the inter-terminal voltage and the charging time when normal charging is performed, which is stored in advance, for judging the presence of abnormality. When required, for example, in exchanging of parts, the information representing the relationship between the inter-terminal voltage and the charging time, which is stored in advance, is updated to new information.