A hammer drill is provided with a connector equipped with a female terminal, movably between a connection position where the female terminal is located inside a plug-in port and a non-connection position where the female terminal is in retreat from inside the plug-in port. The hammer drill is also provided with a torsion spring that urges the connector toward the non-connection position. The connector is provided with a shutter portion that is located inside the plug-in port to close the plug-in port at the non-connection position and is in retreat from inside the plug-in port at the connection position. A dust collecting device is provided with a press rail that comes into abutment on the connector to move the connector to the connection position against the urging of the torsion spring as the dust collecting device is mounted.