1. A management apparatus, which monitors by way of a communication network a communication apparatus that has been detected using credential, the management apparatus comprising: a communication interface device which is coupled to the communication network; a storage resource which stores attribute/protocol management information denoting multiple attribute/ protocol relationships; a processor which is coupled to the communication interface device and the storage resource, wherein the attribute/protocol relationship is a corresponding relationship between a communication apparatus attribute and a management protocol, which is inferred to be the optimum for the communication apparatus having this communication apparatus attribute, and wherein the processor carries out the following processing for each of multiple addresses prior to inputting a credential to be used to detect a communication apparatus: (A) issuing a query specifying an address; (B) writing, in a case where a response to this query has been received from the communication apparatus, which is at the address specified in this query, to the storage, resource query result information, which denotes the corresponding relationship between the address specified in this query and the communication apparatus attribute acquired based on this response; (C) identifying from the attribute/protocol management information a management protocol that corresponds to the communication apparatus attribute denoted by the query result information; and (D) deciding, based on the identified management protocol, the optimum management protocol for this address.