A charging system for a walking robot which charges a battery mounted on the walking robot by connecting a power supplying connector provided in a charging station to a power receiving connector in the walking robot, wherein the walking robot is capable of moving without significant restrictions during charging. The charging system includes a lock mechanism for locking the power supplying connector to the power receiving connector. A connector holder holds the power supplying connector detachably, an advancing/retracting mechanism advances and retracts the connector holder in the anteroposterior direction, and a lock operation mechanism performs a lock operation and an unlock operation of the lock mechanism via the connector holder. After an advance of the connector holder, the lock mechanism performs the lock operation to lock the power supplying connector to the power receiving connector. Thereafter, the connector holder is retracted out of the power supplying connector.