A plant facility apparatus recognition system is provided, which appropriately recognizes a plant facility apparatus even in a plant facility in which a wireless facility and a marker are not able to be installed even when the shape of the plant facility apparatus is different from or has been changed from design data. The plant facility apparatus recognition system that uses a mobile device having a camera to recognize the plant facility apparatus to be subjected to work in the plant facility includes a characteristic length acquirer that acquires information on the pipe as a first characteristic length from an image obtained by causing the camera to image the plant facility apparatus and the pipe existing near the plant facility apparatus, and a characteristic length comparator that compares the first characteristic length with a second characteristic length acquired from the design data and related to the pipe.