This paper describes a fusion of work space and null space force control in a redundant manipulator. In this strategy, work space carries out work space observer based position/force PID control, and null space implements force control. Moreover, passivity based null space controller can guarantee stability of null space motion. Using L2 disturbance suppression property of the system, an influence of force torque to each joint can be suppressed. Desired force response to the object is realized by force PID controller. The validity of the proposed approach is verified by simulations of 4-link redundant manipulator.