The hemostatic device 10 has a flexible band body 20 that can be wound around a portion 220 of the arm where the radial artery 210 and the ulnar artery 230 run, and is fixed in a state where the band body is wound around the arm. Part 30, a first expansion part 50 that is connected to the band and can be expanded by injecting a fluid to press the site to be hemostatic located in the radial artery, and a first expansion part in the longitudinal direction of the band At least a portion of the second dilatation portion 60 is disposed between the second dilation portion 60 and the second dilation portion, which is disposed at different positions and can be expanded by injecting fluid to press the ulnar artery. And an auxiliary balloon 160 that can press the second expansion portion.止血器具１０は、橈骨動脈２１０および尺骨動脈２３０が走行する腕の止血すべき部位２２０に巻き付けることが可能な可撓性を備える帯体２０と、帯体を腕に巻き付けた状態で固定する固定部３０と、帯体に連結されて流体を注入することにより拡張して橈骨動脈に位置する止血すべき部位を押圧可能な第１拡張部５０と、帯体の長手方向において第１拡張部と異なる位置に配置され、かつ、流体を注入することにより拡張して尺骨動脈を押圧可能な第２拡張部６０と、帯体と第２拡張部との間に、少なくとも一部が第２拡張部と重なるように配置され、第２拡張部を押圧可能な補助バルーン１６０と、を有する。
