An air conditioning system comprising: air conditioners (10a, 10b,...)configured from indoor units (11a, 11b,...) installed within rooms (30a, 30b,...) of a building and outdoor units (12a, 12b,...) installed outside the building, the air conditioners (10a, 10b,...) having one or more installed functions of multiple functions; a mobile terminal carried by a user of the air conditioners (10a, 10b,...) and having an air conditioning management program installed thereon for management of the air conditioners (10a, 10b,...); and adaptors (20a, 20b,...) connected on a one-to-one basis to the indoor units (11a, 11b,...) and configured to carry out exchange of information between the air conditioners (10a, 10b,...) and the mobile terminal using Wi-Fi communication between the adaptors (20a, 20b,...) and the mobile terminal and having wired connection between the adaptors (20a, 20b,...) and the air conditioners (10a, 10b,...), characterized in that the air conditioners (10a, 10b,...) are configured to store installed function information which is information classifying a multitude of functions with which the air conditioners (10a, 10b,...) potentially are provided into functions that are actually installed in the air conditioners (10a, 10b,...) and functions that are not installed; the air conditioning system further comprises a server, the server and the adaptors (20a, 20b,...) are constituting information intermediation devices (40, 20a, 20b,...) configured to carry out exchange of installed function information between the air conditioners (10a, 10b,...) and the mobile terminal using a first wireless communication unit of the mobile terminal for access to a public network while the mobile terminal is outside the building and using a second wireless communication unit of the mobile terminal to read out installed function information via the adaptors (20a, 20b,...) using Wi-Fi communication while the mobile terminal is inside the building; and the air conditioning management program is configured to generate an air conditioner management screen image displayed on the display of the mobile terminal in accordance with the read out installed function information. air conditioners (10a, 10b,...)configured from indoor units (11a, 11b,...) installed within rooms (30a, 30b,...) of a building and outdoor units (12a, 12b,...) installed outside the building, the air conditioners (10a, 10b,...) having one or more installed functions of multiple functions; a mobile terminal carried by a user of the air conditioners (10a, 10b,...) and having an air conditioning management program installed thereon for management of the air conditioners (10a, 10b,...); and adaptors (20a, 20b,...) connected on a one-to-one basis to the indoor units (11a, 11b,...) and configured to carry out exchange of information between the air conditioners (10a, 10b,...) and the mobile terminal using Wi-Fi communication between the adaptors (20a, 20b,...) and the mobile terminal and having wired connection between the adaptors (20a, 20b,...) and the air conditioners (10a, 10b,...), characterized in that the air conditioners (10a, 10b,...) are configured to store installed function information which is information classifying a multitude of functions with which the air conditioners (10a, 10b,...) potentially are provided into functions that are actually installed in the air conditioners (10a, 10b,...) and functions that are not installed; the air conditioning system further comprises a server, the server and the adaptors (20a, 20b,...) are constituting information intermediation devices (40, 20a, 20b,...) configured to carry out exchange of installed function information between the air conditioners (10a, 10b,...) and the mobile terminal using a first wireless communication unit of the mobile terminal for access to a public network while the mobile terminal is outside the building and using a second wireless communication unit of the mobile terminal to read out installed function information via the adaptors (20a, 20b,...) using Wi-Fi communication while the mobile terminal is inside the building; and the air conditioning management program is configured to generate an air conditioner management screen image displayed on the display of the mobile terminal in accordance with the read out installed function information.