To detect that any anomaly occurs in a charging circuit or the like, including a capacitor.

A capacitor charging device comprises an electric double layer capacitor 44, the charging circuit 42 that charges the capacitor 44, and a terminal voltage detection circuit 45 that detects the voltage between the terminals of the capacitor 44. An nonvolatile RAM stores past data of change over time in the terminal-to-terminal voltage detected by the terminal voltage detection circuit 45 when the capacitor 44 is charged or discharged. Time change in the voltage detected when the capacitor 44 is charged or discharged and the past data stored in the nonvolatile RAM are compared with each other. If the result of comparison reveals that there is a difference equal to or greater than a predetermined first value between the time change in the detected voltage and the past data, it is determined that some anomaly has occurred in the circuit or the like including the capacitor 44.