A distributor (10, 11, 12, 13, 14) comprising: a first plate, a second plate, and a third plate, the first plate being stacked on the second plate in a stacking direction, the second plate being stacked on the third plate in the stacking direction, the first plate having a first through hole, the second plate having a first hollow portion communicating with the first through hole, a plurality of second hollow portions communicating with the first hollow portion, and a plurality of third hollow portions each communicating with its associated one of the plurality of second hollow portions, the third plate having a plurality of second through holes each communicating with its associated one of the plurality of third hollow portions, the first hollow portion having an elongate shape having a length along which a fluid flows and a width orthogonal to the length in a plane perpendicular to the stacking direction, the plurality of second hollow portions each having an elongate shape having a length along which the fluid flows and a width orthogonal to the length in the plane perpendicular to the stacking direction, wherein L1 is larger than L2 where L1 is a first dimension that is the width of the first hollow portion, and L2 is a second dimension that is the width of each of the plurality of second hollow portions, characterised in that the plurality of second through holes each have an elongate shape having a length and a width orthogonal to the length in the plane perpendicular to the stacking direction, wherein L4 is smaller than L3 where L3 is a third dimension that is a width of each of the plurality of third hollow portions, and L4 is a fourth dimension that is the width of each of the plurality of second through holes, and wherein L5 is larger than L6 where L5 is a fifth dimension that is the length of each of the plurality of second through holes, and L6 is a sixth dimension that is a length of each of the plurality of third hollow portions. a first plate, a second plate, and a third plate, the first plate being stacked on the second plate in a stacking direction, the second plate being stacked on the third plate in the stacking direction, the first plate having a first through hole, the second plate having a first hollow portion communicating with the first through hole, a plurality of second hollow portions communicating with the first hollow portion, and a plurality of third hollow portions each communicating with its associated one of the plurality of second hollow portions, a first hollow portion communicating with the first through hole, a plurality of second hollow portions communicating with the first hollow portion, and a plurality of third hollow portions each communicating with its associated one of the plurality of second hollow portions, the third plate having a plurality of second through holes each communicating with its associated one of the plurality of third hollow portions, the first hollow portion having an elongate shape having a length along which a fluid flows and a width orthogonal to the length in a plane perpendicular to the stacking direction, the plurality of second hollow portions each having an elongate shape having a length along which the fluid flows and a width orthogonal to the length in the plane perpendicular to the stacking direction, wherein L1 is larger than L2 where L1 is a first dimension that is the width of the first hollow portion, and L2 is a second dimension that is the width of each of the plurality of second hollow portions, characterised in that the plurality of second through holes each have an elongate shape having a length and a width orthogonal to the length in the plane perpendicular to the stacking direction, wherein L4 is smaller than L3 where L3 is a third dimension that is a width of each of the plurality of third hollow portions, and L4 is a fourth dimension that is the width of each of the plurality of second through holes, and wherein L5 is larger than L6 where L5 is a fifth dimension that is the length of each of the plurality of second through holes, and L6 is a sixth dimension that is a length of each of the plurality of third hollow portions.