An information system includes a housing with a plurality of units mounted thereon, a communication path built in the housing to take charge of information communication between a plurality of the units mounted on the housing, an information unit mounted on the housing to provide and process the information, a plurality of communication units each mounted on the housing to independently relay the information communication between the information unit and a device external to the housing, and a management unit for accessing the whole or a part of the plurality of the units mounted on the housing and acquiring internal information of the units accessed, wherein in the case where all the plurality of the communication units accessed are incommunicable, the internal information acquired from the plurality of the communication units is reported to the device external to the housing without passing through the plurality of the communication units.