Disclosed is an electrochemical capacitor which comprises an element, an electrolyte, and an outer case that houses the element and the electrolyte. The element comprises: a negative electrode that is obtained by forming a negative electrode layer on the surface of a collector, the negative electrode layer containing a carbon material in which lithium ions are absorbed; a positive electrode that is obtained by forming a positive electrode layer on the surface of a collector, the positive electrode layer absorbing ions; and a separator that is interposed between the negative electrode and the positive electrode. The electrolyte contains lithium ions. A coating film that contains lithium carbonate is formed on the surface of the carbon material that is contained in the negative electrode layer.