The present invention has an object of providing a blood sampling device that can collect a small amount of blood and prevent blood leakage. The present invention provides a blood sampling device comprising a pipette tip-shaped blood sampler having an internal space for aspirating and holding blood by the capillary action and having openings at the top and bottom, a cylindrical container capable of accommodating the blood sampler and a cap piston-shaped sealing cap for sealing the container, wherein a receiving part is provided at the bottom of the container and a locking part and a screw part are provided on the upper outer side of the container, and a mandrel extending from the inner upper surface of the sealing cap is provided and a projection and a screw part are provided on the inner side surface of the sealing cap.