1. A network communication apparatus that includes a network port for connecting to a telephone line and a communication unit that communicates with an external apparatus via the telephone line, comprising: an auto-shutdown unit configured to execute shutdown processing for stopping supply of electric power to the network communication apparatus when an auto-shutdown shifting time period elapses without receiving a user's operation; a line detection unit configured to detect whether or not the network port is connected to the telephone line; a selection unit configured to select, based on a user's operation, whether or not to cause said auto-shutdown unit to execute the shutdown processing; and a notification unit configured to notify a user that the shutdown processing cannot be executed, in a case where to cause said auto-shutdown unit to execute the shutdown processing is selected by said selection unit, and also it is detected by said line detection unit that the network port is connected to the telephone line.