An air-conditioning system includes equipment, the equipment including one or more pieces of equipment, a high level device connected to the equipment and configured to control the equipment, a first communication unit configured to obtain, from an update management device that previously stores an update program for updating a program of the equipment, the update program, a second communication unit configured to transmit the update program to the equipment and obtain a pre-update program from the equipment, a storage device configured to store the update program and the pre-update program, and an update execution unit configured to update the program of the equipment, in which the update execution unit transmits the update program to the equipment and updates the program of the equipment, and when one of the one or more pieces of the equipment in which the program is updated does not operate normally, the update execution unit transmits the pre-update program to the one of the one or more pieces of the equipment and restores the program of the one of the one or more pieces of the equipment to the pre-update program.