An electrolyte solution capable of providing electrochemical devices whose internal resistance is less likely to increase even after repeated charge and discharge and whose cycle capacity retention ratio is high. The electrolyte solution contains a solvent, an electrolyte salt, and at least one selected from the group consisting of compounds represented by R11X11—SO3M11 and compounds represented by R21R22N—SO3M21 in an amount of 0.001 to 10 mass % relative to the solvent.
