The paper describes the fabrication of single-electron transistors and circuits using silicon-on-insulators (SOIs). We first point out that control of the oxidation of Si is quite important and could be the key to the fabrication of quantum devices including single-electron devices. We then introduce our technique for making single-electron transistors, which uses special phenomena that occur during the oxidation of SOIs, and show that the technique enables us to realize primary single-electron circuits as a result of its high controllability, reproducibility and thermal stability. (C) 2002 Elsevier Science Ltd. All rights reserved.