To limit an environment that can be used finely, by selecting which environment between IPv4 and IPv6 can be used in each function or each communication protocol.

This image forming apparatus 21 capable of performing communication via a network can select and use one between IPv4 and IPv6 as a communication method, is provided with a set table, wherein whether to use IPv4, to use IPv6 or to use both of them are set in each use function, requested from the operation part of a PC 24 that is a terminal device or the image forming apparatus, and is used for communication which selects either IPv4 or IPv6, in accordance with the requested use function with reference to the set table to execute the requested function.