This article discusses the five-string kantele as an example of the Finnish national heritage, a school instrument and an example of sustainable design. A qualitative case study was made by collecting the data from the Finnish students--prospective teachers--and the sixth form pupils, who had designed and carved their own five-string kanteles. The purpose of this research was to find out which aspects of five-string kantele design are considered the most important for sustainable principles and design among these youngsters. As results, the elements and principles of designing the five-string kantele are discussed and its relevance to five sustainable characteristics (creative, ecological, economic, aesthetic and socio-environmental) is presented. The sustainable values of the kantele and the purpose for which it is made are also considered.