A communication control device connected between an image forming apparatus and a communication line in an image forming apparatus supervising system which connects the image forming apparatus and a host machine by the communication line. Assume that particular data of an image forming apparatus and which is updated day by day should be read periodically. Then, even when the power supply to the image forming apparatus is shut off, a host machine can access the apparatus to read the data which should be read periodically, and receive it. In addition, the data can be preserved until the next time for reading. The data is stored in a first memory until the data is ready for transfer to the host machine, at which time the data is transferred to a second memory and then to the host machine.