Octopus suction cup has the micro bumps or trenches. These micro structure will be effective for a performance of adhesion. We reported the vacuum gripper imitating an adhesion principle of octopus. This gripper can grasp the rigid object with flat, curved, and uneven surface. In this paper, we evaluated the effect of micro bumps using the octopus-bioinspired vacuum griper added the bumps which is 2[μm] in diameter and 4[μm] in pitch. The adhesion force of gripper with micro bumps was higher than that of gripper without micro bumps, since the friction force between gripper and object was increased by bumps. Moreover, the shear force of peering was increased by adding micro bumps to gripper.