An information service program which causes an information service apparatus perform processing of information service about optional devices which are mountable in an object apparatus, the processing including a process of determining present configuration of the object apparatus including mounted optional devices which are mounted in the object apparatus, and non-mounted optional devices which are optional devices which are not mounted but are mountable in the object apparatus, by acquiring information about mounting status of the optional devices in the object apparatus and a process of displaying an appearance image of the object apparatus, which is to be configured when the non-mounted object devices are further additionally mounted in the object apparatus, to a user so that the user can discriminate between the present configuration of the object apparatus and the non-mounted optional devices.