The electrochemical window of the LiCl-KCl-CsCl melt (57.5:13.3:29.2 mol %, m. p.; 538 K) was investigated at 573-723 K. The cathodic limit of this melt for a nickel electrode was confirmed as lithium deposition from the results of differential scanning calorimetry and inductively coupled plasma atomic emission spectroscopy. Concerning the anodic limit of this melt, chlorine was confirmed to be evolved on a glassy carbon electrode from the result of the gas analysis. The electrochemical windows were determined as 3.75 and 3.62 V at 573 and 723 K, respectively. These values agreed well with theoretical decomposition voltages of LiCl. (C) 2004 The Electrochemical Society.