This paper describes a new user interface, called a fingerprint user interface (FUI), which employs fingerprint recognition. While the unique feature patterns of fingerprints have mainly been used for personal identification, the FUI is unique in that it uses not only the differences among fingerprint patterns of different persons, but also the differences among the ten fingers of a single person. In the FUI, the system identifies the finger that has operated (touched) an input device through pattern matching of fingerprints and it performs the task assigned to the identified finger. Since users are able to specify different tasks by using different fingers, they feel as if commands and data objects were actually held on their fingers.