Yes; the device has a rechargeable battery. If the device is in standby mode, this lasts for approx. 24 hours; otherwise it is also empty after 6-8 hours and must be charged.
Thanks for the answers, but I'm not sure if the question has been understood correctly. Therefore, I will formulate it in more detail. I have the following scenario: The router is connected to a Linux PC via USB. The Linux PC sees the router as a local LAN. The power goes out and comes back on after a few seconds. The PC reboots. Will the router also be switched on, or does it have to be switched on again manually?