CELL, CELL STACK DEVICE, MODULE, AND MODULE HOUSING DEVICE

A cell includes an element portion and a support substrate. The support substrate includes a gas-flow passage through which the reactive gas flows in a first direction, and supports the element portion. The element portion includes a first portion having a first length in a second direction intersecting the first direction, and a second portion located on a downstream side in the gas-flow passage relative to the first portion, the second portion having a second length in the second direction different from the first length in the second direction.