To facilitate ombre dyeing on the root of a hair with a simple structure.

This hair dyeing brush 10 comprises a long-sized brush body 11, a brush part 12, and a comb part 13. On one side surface of a brush block 11A, the brush part 12 is formed by arranging and transplanting, at a predetermined interval, a plurality of brush bristle bundles 16 formed by bundling many brush bristle extending in the direction orthogonal to the longitudinal direction of the brush body 11, and the comb part 13 is formed on the other side surface of the brush block 11A. The brush block 11A is formed curvedly, the tip of each brush bristle bundle 16 is formed in a three-dimensionally tapered shape like a writing brush, length of the brush bristle bundle 16 is gradually increased as they go to both ends, and a connecting line between tips of respective brush bristle bundles 16 is formed in a curve Rs shape.