A method and device for pattern processing whereby accurate and effective processing can be carried out as a user desires. A pattern processing device of this invention comprises an information input/output device, an information processing device, and a data storage device; wherein the information processing device comprises pattern processing means, significance describing means, characteristic information input means, characteristic information extraction means, characteristic information describing means, and pattern processing means making reference to characteristic information. Intentions of a user or characteristics of pattern elements or sets of pattern elements are described and added to the pattern data so that this characteristic information can be referred to when pattern data processing is carried out. Thus, it is possible to make accurate representation of pattern data in a computer, and it is also possible to generate or convert patterns as the user desires.