It is an object of the present invention to provide an electrochemical device having an electrolytic solution having high current density and high oxidation resistance, as well as high safety, where dissolution and deposition of magnesium progress repeatedly and stably.The present invention relates to the electrolytic solution for an electrochemical device comprising (1) the supporting electrolyte composed of a magnesium salt and (2) at least one or more kinds of the compound represented by the following general formula [2], as well as the electrochemical device comprising said electrolytic solution, a positive electrode, a negative electrode and a separator.