To surely inform a user of charging information, such as the completion of the charging of a battery.

This charging device 10 is used for charging the battery 22 of an electric tool, and comprises a charging control means 34 which controls the charging of the battery 22, and a portable telephone control manes 41 which is constituted so as to be capable of controlling a portable telephone 40a, on the basis of the signal from the charging control means 34.