ELECTROCHEMICAL CELL

An electrochemical cell includes a first single cell including a first power generation element and a first inner container which accommodates the first power generation element, a second single cell including a second power generation element and a second inner container which accommodates the second power generation element, and an outer container which accommodates the first single cell and the second single cell, and the first single cell and the second single cell are stacked, and the electrochemical cell includes at least one welded portion in which the first inner container and the second inner container are welded to each other.