The gas liquid separator comprises a gas liquid separator-forming portion formed in an end plate of a fuel cell to have an opening at an end face of the end plate and that constitutes part of the gas liquid separator; and a cover member located to cover the opening and is combined with the gas liquid separator-forming portion to constitute the gas liquid separator. The gas liquid separator-forming portion includes a first inner wall portion provided to serve as a flow path of the off-gas and form part of a reservoir and that is configured to include an off-gas outlet, to be connected with the opening and to be formed concave in a thickness direction of the end plate; and a surrounding portion protruded from the first inner wall portion along a first direction from the gas liquid separator-forming portion toward the cover member to surround the off-gas outlet.