A stacking-type header according to the present invention includes: a first plate-shaped unit having a plurality of first outlet flow passages formed therein; and a second plate-shaped unit stacked on the first plate-shaped unit, the second plate-shaped unit having a distribution flow passage formed therein, the distribution flow passage being configured to distribute refrigerant, which passes through a first inlet flow passage to flow into the second plate-shaped unit, to the plurality of first outlet flow passages to cause the refrigerant to flow out from the second plate-shaped unit, in which the distribution flow passage includes a branching flow passage including a straight-line part perpendicular to a gravity direction, and in which the refrigerant flows into the branching flow passage through a part between both ends of the straight-line part, passes through both the ends, and flows out from the branching flow passage through a plurality of end portions.