To provide a suction cup having strong fixed power even if it is fixed on an irregular surface.

The suction cup 100 comprises: a suction cup body 1 sucking the irregular surface M, and depressurizing a space 13 between the suction cup body and the irregular surface M by applying a force in a direction of pulling up the suction cup body in a state of sucking the irregular surface; a case 2 disposed to cover the suction cup body 1 and pressing the suction cup body 1 toward the irregular surface M by applying a force to the suction cup body 1; and a sealing member 3 disposed on a lower surface edge part of the suction cup body 1 to be in close contact with the irregular surface M. A projecting part 24 is disposed between the suction cup body 1 and the case 2 so that the suction cup body 1 and the case 2 are closely contact with each other.