The present invention provides an electrochemical cell including: an electrode body; an exterior packaging body in which a plurality of substrates including a first substrate formed from a ceramic material are stacked in the first direction, and a cavity in which the electrode body is accommodated is formed; a first electrode connection wiring that is formed in the exterior packaging body and connects a first electrode layer and an external substrate to each other; and a second electrode connection wiring that is forming in the exterior packaging body and connects a second electrode layer and the external substrate to each other. At least the first electrode connection wiring is formed in the first substrate, and an attachment portion, to which a fastening member configured to mount at least the first electrode connection wiring to the external substrate is attached, is formed in the first substrate.