Cooperation information managing apparatus and gateway apparatus for use in cooperation information managing system

In a system including a first unit retaining a first identifier and a second unit retaining a second identifier for reading out the first identifier from the first unit to transmit, as cooperation information, a combination of the first identifier and the second identifier, for managing the cooperation information, a cooperation information managing apparatus receives the cooperation information and registers the second identifier included in the cooperation information and a group of a plurality of first identifiers including the first identifier included in the cooperation information in a state associated with each other. For managing objects to be used by a user, this enables managing the objects as an aggregation without handling the objects individually, thereby realizing efficient management from a user's point of view.