An image processing apparatus which, when an error occurs during communication with a host computer, gives a higher priority to reconnection to the host computer connected at the time of occurrence of the error than to connection to another host computer. A CPU of the apparatus accepts processing requests from the host computers. When accepting a processing request from a host computer, the CPU causes the apparatus to connect to the host computer. If occurrence of an error is detected during communication with the host computer, the CPU controls the connection such that reconnection to the host computer connected at the time of occurrence of the error is given priority over connection to another host computer.