The invention relates to an electrolyte for an electrochemical device. This electrolyte includes a first compound that is an ionic metal complex represented by the general formula (1); and at least one compound selected from special second to fourth compounds, fifth to ninth compounds respectively represented by the general formulas Aa+(PF6−)a, Aa+(ClO4−)a, Aa+(BF4−)a, Aa+(AsF6−)a, and Aa+(SbF6−)a, and special tenth to twelfth compounds, The electrolyte is superior in cycle characteristics and shelf life as compared with conventional electrolytes.