An electrochemical device of this invention has a stacked member, in which a plurality of collectors having polarizable electrode layers formed on the surfaces thereof and a plurality of separators which separate the adjacent polarizable electrode layers are arranged in alternation, and a pair of fixed collecting plates arranged on both sides in the stacking direction of the stacked member. The pair of fixed collecting plates has a depressed portion which exerts pressure on the stacked member and a protruding portion which forms a gap with the stacked member. The protruding portions terminate at the peripheral portions of the fixed collecting plates so that gaps are formed between the stacked member and the fixed collecting plates. These gaps serve as permeation apertures for electrolytic solution.