An EGR gas cooler according to one aspect of the present invention is provided with: a case that has a pair of opposing end surfaces and a pair of opposing side surfaces, and that, by means of the pair of end surfaces and pair of side surfaces, sections off a flow channel through which an EGR gas flows vertically downward; a fin group comprising a plurality of fins positioned in the flow channel and aligned parallel to the pair of end surfaces; a tube which passes through the fins of the fin group and inside of which a refrigerant flows; and barriers that are disposed along the side surfaces and that extend horizontally.