Disclosed herein is a suction cup used in a vacuum system. The suction cup includes a hollow body, a skirt-shaped pad disposed under the body, and a ring-shaped clamp removably provided in the suction cup to couple the body with the pad. A concave ‘C’-shaped outer surface of the clamp compresses a contact portion of the body with the pad in opposite directions upwards and downwards while surrounding the contact portion, thus coupling the body with the pad.