SEPARATOR STRUCTURE

Each plate includes: a rectangular plate body; and a seal structure unit provided along an outer periphery of the plate body and projecting in a thickness direction of the plate body from the plate body. The seal structure unit includes: a band-shaped flat part separated in the thickness direction from the plate body and provided parallel to the plate body; a first connection part connecting the plate body and one end of the flat part in a width direction thereof to each other; and a second connection part connecting the plate body and the other end of the flat part in the width direction to each other. A boundary between the plate body and the first connection part and a boundary between the plate body and the second connection part are each formed into a linear shape when viewed in the thickness direction. The other end is formed into a concave-convex shape when viewed in the thickness direction.