A laminated header, comprising: a plurality of plate-like members (111 to 116, 121 to 125), each of the plurality of plate-like members (111 to 116, 121 to 125) being laminated with each other; one first opening; a plurality of second openings; and a distribution flow passage formed though the plurality of plate-like members and connecting the one first opening and each of the plurality of second openings to each other, the distribution flow passage comprising: a first passage having a straight line shape; a first branching flow passage for the first passage to branch into a plurality of passages; a second passage having a straight line shape and connected to each of the plurality of passages branched in the first branching flow passage; a second branching flow passage for the second passage to branch into a plurality of passages; and a third passage having a straight line shape and connected to each of the plurality of passages branched in the second branching flow passage, the first passage, the second passage, and the third passage being circular through holes formed in two or more of the plurality of plate-like members (111 to 116, 121 to 125), the laminated header being characterized in that the distribution flow passage is such that, in use, the refrigerant flows into it, through the first passage and the second passage in directions opposite and reverse to each other, and through the second passage and the third passage in directions opposite and reverse to each other. a plurality of plate-like members (111 to 116, 121 to 125), each of the plurality of plate-like members (111 to 116, 121 to 125) being laminated with each other; one first opening; a plurality of second openings; and a distribution flow passage formed though the plurality of plate-like members and connecting the one first opening and each of the plurality of second openings to each other, the distribution flow passage comprising: a first passage having a straight line shape; a first branching flow passage for the first passage to branch into a plurality of passages; a second passage having a straight line shape and connected to each of the plurality of passages branched in the first branching flow passage; a second branching flow passage for the second passage to branch into a plurality of passages; and a third passage having a straight line shape and connected to each of the plurality of passages branched in the second branching flow passage, a first passage having a straight line shape; a first branching flow passage for the first passage to branch into a plurality of passages; a second passage having a straight line shape and connected to each of the plurality of passages branched in the first branching flow passage; a second branching flow passage for the second passage to branch into a plurality of passages; and a third passage having a straight line shape and connected to each of the plurality of passages branched in the second branching flow passage, the first passage, the second passage, and the third passage being circular through holes formed in two or more of the plurality of plate-like members (111 to 116, 121 to 125), the laminated header being characterized in that the distribution flow passage is such that, in use, the refrigerant flows into it, through the first passage and the second passage in directions opposite and reverse to each other, and through the second passage and the third passage in directions opposite and reverse to each other.