1. A material output system comprising: a server comprising storage medium, said server storage medium storing at least one piece of meeting information, the meeting information including prospective participants in a meeting, a meeting room where said meeting is held, a meeting room use time for said meeting, and a storage location to save material used in said meeting; a plurality of output hardware units configured to output said material, each said output hardware unit being located in a meeting room and comprising a processor, a display unit, and authentication hardware authenticating a user; where said server storage medium further stores a correspondence between said plurality of output hardware units and meeting rooms corresponding to said plurality of output hardware units; said output hardware unit that performed authentication of the user being instructed to output material saved in the storage location of the meeting information when i) it is determined based on said meeting information that said user authenticated by said authentication hardware is one of the prospective participants for said meeting and it is determined based on said meeting information that the present date and time is included in the meeting room use time for said meeting, and ii) it is determined based on said correspondence stored in said server storage medium that said output hardware unit that performed authentication of the user corresponds to the meeting room where said meeting is held; said display unit displaying a screen to allow output of material saved in the storage location for at least one piece of meeting information when said authenticated user is one of a plurality of prospective participants in the meeting information for a meeting when it is determined that said server storage medium does not store meeting information where said authenticated user is one of a plurality of prospective participants in a meeting, where a meeting room corresponded with said output hardware unit has performed authentication of the user is the meeting room where the meeting is held, and where the present date and time is included in a meeting room use time in the meeting information for the meeting; and said output hardware unit that has performed authentication to output material being instructed, based on an instruction from said authenticated user, to save in the storage location of the meeting information for a meeting when said screen to allow output of material is displayed on said display unit and when said authenticated user is one of the prospective participants in the meeting information for a meeting.