An apparatus management system, comprising: a management device configured to remotely manage apparatus information related to an apparatus; and an information communication device connected to the apparatus to obtain the apparatus information and transmit the apparatus information to the management device by communicating with the management device through a communication network, wherein the management device is configured to be connected to the information communication device through a closed network that connects the management device and the information communication device in a secure state, the closed network being isolated in terms of access from an open network in the communication network, when the management device is connected to the information communication device through the closed network, the management device is configured to perform authentication determination on the information communication device and transmit a device certificate to the information communication device after completing authentication of the information communication device, the device certificate including information indicating that the information communication device has been authenticated and encryption information for encrypting information that is transmitted from the information communication device to the management device, and when the information communication device is connected to the management device through the closed network in a secure connectior state, the information communication device transmits first authentication information for verifying the information communication device to the management device, and the management device is configured to authenticate the information communication device in the secure connection state with information for authenticating the information communication device that is second authentication information stored in advance in a storage unit and the first authentication information obtained from the information communication device, and transmit the device certificate to the information communication device in the secure connection state with the management device after completing authentication of the information communication device. a management device configured to remotely manage apparatus information related to an apparatus; and an information communication device connected to the apparatus to obtain the apparatus information and transmit the apparatus information to the management device by communicating with the management device through a communication network, wherein the management device is configured to be connected to the information communication device through a closed network that connects the management device and the information communication device in a secure state, the closed network being isolated in terms of access from an open network in the communication network, when the management device is connected to the information communication device through the closed network, the management device is configured to perform authentication determination on the information communication device and transmit a device certificate to the information communication device after completing authentication of the information communication device, the device certificate including information indicating that the information communication device has been authenticated and encryption information for encrypting information that is transmitted from the information communication device to the management device, and when the information communication device is connected to the management device through the closed network in a secure connectior state, the information communication device transmits first authentication information for verifying the information communication device to the management device, and the management device is configured to authenticate the information communication device in the secure connection state with information for authenticating the information communication device that is second authentication information stored in advance in a storage unit and the first authentication information obtained from the information communication device, and transmit the device certificate to the information communication device in the secure connection state with the management device after completing authentication of the information communication device.