To avoid update to a program not based on a security standard.

A CPU 1 of an MFP 100 acquires an update program from an external device 26 or the like on a network 25, decides whether the update program and an update target program installed to the MFP 100 are respectively based on the prescribed security standard or not, and prohibits the program update when a decision result thereof shows that the update target program is based on the security standard and that the update program is not based on the security standard. In that case, the CPU 1 notifies the outside about the effect, or notifies the outside about inquiry information about whether to continue the program update or not. The program update is continued when an instruction to continue the program update is performed to the notification, and the program update is stopped when an instruction to stop the program update is performed.