The present invention realizes lower power consumption of an entire system in a case in which a battery operated electronic device such as an image pickup apparatus is used as a USB host machine. When a battery powered electronic device is connected via a cable to an external device that receives a supply of power from a host machine, which is the electronic device, the present invention provides a function to switch the external device to a low power consumption state under a predetermined condition, and a function to allow the external device to recover to an ordinary state. Also, a function is provided to check whether or not the low power consumption state of the external device satisfies the predetermined condition.