This paper presents design of a 6 DOF haptic master which is based on a combination of a planar 3 DOF parallel mechanism and a spatial 3 DOF parallel mechanism. Since low inertia is vital to backdrivability and transparency of the haptic device, all actuators are placed on the base and thus some forces for haptic feedback are transmitted by tendon-driven mechanism. This device was intended to teleoperate a mobile manipulator, which requires planar 3 DOF motion for navigation of the vehicle and full 6 DOF motion for manipulation. Therefore, the proposed device is designed to have two modes of a planar task and a 3D task which are switchable without any change in hardware. This feature provides efficient actuation and reduces computational burden since only 3 actuators are involved in the case of a planar task. The paper deals with a detailed description of the proposed haptic master and Jacobian analysis. Some applications are given to verify the validity of this device.