Provided is an electrochemical device which is compatible with high-temperature reflow soldering using lead-free solder. An electric double-layer capacitor 10-1 has a structure in which a positive terminal 12 and a negative terminal 13 are led out of a package 14 where an electric storage element 11 is sealed. The entire package 14 and the bases of led-out portions of the positive terminal 12 and the negative terminal 13 are covered by a thermal insulation material layer 16 having a thermal conductivity lower than that of the package 14.