The uterine hemostatic balloon unit includes a tube, a hemostatic balloon, a connector disposed in the tube, and a cap to be detachably attached to a proximal end portion of the tube. The tube has a drain channel for draining uterine blood outward and a water supply channel communicating with the hemostatic balloon. The connector has a drain terminal communicating with the drain channel and disposed in a proximal end portion of the tube, a flexible water supply tube communicating with the water supply channel and extending by being bifurcated outward of the tube, and a water supply terminal communicating with the water supply tube. The cap has an accommodating portion capable of accommodating the water supply terminal along a length direction of the drain terminal. The accommodating portion is open in a direction orthogonal to the length direction of the drain terminal.