The present invention addresses the problem of providing an electrophoretic medium container capable of stabilizing a liquid delivery pressure while ensuring sealing of an electrophoretic medium. In order to resolve this problem, this electrophoretic medium container is provided with a syringe part for holding an electrophoretic medium, and a sealing component for sealing one end of the syringe part, the electrophoretic medium container being characterized in that the sealing component has a sealing surface, a body part, and a groove provided between the sealing surface and the body part, wherein the sealing surface is in contact with the inner wall of the syringe part.