Nonvolatile electrochromic element and method for controlling movement of cations

A nonvolatile electrochromic element (1) equipped with: a cation movement part (4) comprising a cyano-bridged metal complex represented by the chemical formula A x M[L(CN) 6 ] y ∙nH 2 O; and a movement barrier part (7) disposed in an inner part of or on a surface of the cation movement part (4), the movement barrier part (7) comprising a cyano-bridged metal complex containing an alkali metal A', which is at least one alkali metal having a larger atomic radius than the alkali metal A of the cyano-bridged metal complex constituting the cation movement part (4). Thus, nonvolatility is imparted to an electrochromic element made using a cyano-bridged metal complex.