In this paper, a method for dividing grasping and manipulating control into grasp plane control and inside grasp plane control is proposed. Grasp plane control is realized by controlling center of gravity (COG) of three end-effectors and posture of the grasp plane. Inside grasp plane control is realized by controlling grasping shape and contact force which exists on the grasp plane. To avoid any danger entailed by dropping of a grasped object, a method for compensating contact force to a grasped object by external force is also proposed. This external force is estimated from normal force, and this force is not affected by frictional force. Thus, stable grasping and manipulating control taking external force parallel to the grasp plane into account is realized. The validity of the proposed systems is confirmed by the experimental results.