A device management system, comprising: a server communicatively connected to a network; a plurality of base stations communicatively connected to the network, the plurality of base stations being low-power wide-area, LPWA, base stations; and a device that communicatively connects to one base station among the plurality of base stations and that sequentially transmits, to the server via the one base station, operation information indicating a current operation state of the device, wherein upon sequentially receiving the operation information, each of the plurality of base stations sequentially transmits, to the server, unique information which is unique to the base station together with the operation information that is sequentially received, and the server: sequentially receives the operation information and the unique information, and sequentially stores, in association with each other, the operation information and the unique information that are sequentially received at a corresponding time; and when first unique information received at a first time and second unique information received at a second time after the first time are different, separately manages a plurality of items of first operation information received in a first period ending at the first time and a plurality of items of second operation information received in a second period starting at the second time. a server communicatively connected to a network; a plurality of base stations communicatively connected to the network, the plurality of base stations being low-power wide-area, LPWA, base stations; and a device that communicatively connects to one base station among the plurality of base stations and that sequentially transmits, to the server via the one base station, operation information indicating a current operation state of the device, wherein upon sequentially receiving the operation information, each of the plurality of base stations sequentially transmits, to the server, unique information which is unique to the base station together with the operation information that is sequentially received, and the server: sequentially receives the operation information and the unique information, and sequentially stores, in association with each other, the operation information and the unique information that are sequentially received at a corresponding time; and when first unique information received at a first time and second unique information received at a second time after the first time are different, separately manages a plurality of items of first operation information received in a first period ending at the first time and a plurality of items of second operation information received in a second period starting at the second time. sequentially receives the operation information and the unique information, and sequentially stores, in association with each other, the operation information and the unique information that are sequentially received at a corresponding time; and when first unique information received at a first time and second unique information received at a second time after the first time are different, separately manages a plurality of items of first operation information received in a first period ending at the first time and a plurality of items of second operation information received in a second period starting at the second time.