Abstract
This chapter reviews various functional properties of HEAs: electrical properties (including superconducting), magnetic properties, electrochemical properties, and hydrogen storage properties. Interesting phenomena and potentially promising properties better than those of conventional alloys have been observed. These indicate that HEAs provide attractive functional properties to be explored and developed from both academic and application-oriented viewpoints. In this chapter, compositions, process parameters, and microstructure will be correlated with functional properties to give a better understanding.