A cupping device is provided to prevent damage to a user's skin or pain even if the cupping device is placed on the user's skin for a long period of time, by expanding a skin contact surface at a large curvature. An adsorption tool(11) is formed on a spherical body(10) of a cupping device. A suction valve(20) is installed on a perpendicular line that divides the spherical body into two parts. The spherical body forms an expanded skin contact surface on the adsorption tool at a uniform curvature. The suction valve is installed on an eccentric position that is away from the perpendicular line that divides the body into two parts at a predetermined angle. The suction valve is installed on one side or both sides of the horizontal line that crosses the spherical body.
