Polymer electrochemical device

An electrochemical device which comprises a molding containing as a main ingredient a copolymer (Z) and at least two mutually insulated electrodes in joint with the molding, wherein the copolymer (Z) (1) contains only an α-methylstyrene unit as an aromatic vinyl compound unit, (2) comprises a polymer block (A) having as a main unit an α-methylstyrene unit and a polymer block (B) which is incompatible with the polymer block (A) and has as a main unit at least one unit selected from the group consisting of an alkene unit having 2 to 8 carbon atoms, a cycloalkene unit having 5 to 8 carbon atoms, a vinylcycloalkene unit having 7 to 10 carbon atoms, a conjugated alkadiene unit having 4 to 8 carbon atoms and a conjugated cycloalkadiene unit having 5 to 8 carbon atoms;

• and a vinylcycloalkene unit having 7 to 10 carbon atoms, a conjugated alkadiene unit having 4 to 8 carbon atoms and a conjugated cycloalkadiene unit having 5 to 8 carbon atoms in which units, part or all of carbon-carbon double bonds are hydrogenated, and (3) has an ion-conducting group on the polymer block (A).