Nanoclusters the size range of 1- 10 nm can be regarded as the smallest and tunable function units, and we will explore to newly design the cluster-based, nanoassembled functional systems. We focus to establish new nano-material science consisting of nanoclusters through fine controlled synthesis, designer assembly, characterization of advanced functional nanoclusters. In particular, we focus metal atom-encapsulated silicon cage clusters and organometallic sandwich clusters, and also to characterize their electronic properties. With uniform immobilization of the nanoclusters with the aid of self-assembled monolayers, the electronic and optical properties of the formed cluster material are investigated, and a new electronic- and optomagneto-nanodevices consisting of functional nanoclusters are developed.