Provided is a plant equipment state gathering system which simplifies the work relating to attaching and/or replacing a detection device that detects the state of plant equipment. A plant equipment state gathering system 1 is provided with a detection device 10, a mobile terminal 40, a network construction device 20 and a data storage device 30. The detection device 10 includes a tag unit 14 that can store, in a non-contact manner, at least some setting information that at least includes network information for connecting to the network from the mobile terminal 40. The mobile terminal 40 includes a tag control unit 43 that allows the tag unit 14 of the detection device 10 to automatically store, in a non-contact manner, at least some of the setting information. When network information is stored in the tag unit 14 of the detection device 10 by the mobile terminal 40, the network construction device 20 uses this network information to determine whether to allow the connection of the detection device 10 to the
