In this paper, a novel, compact and three degree-of-freedoms (DOFs) micropositioner with large travel ranges is presented. The design of the micropositioner utilizes the monolithic parallel flexure mechanism with the built-in electromagnetic actuators and uses the optical sensors to achieve the object of 3-DOF precise motion. An adaptive sliding-mode controller is proposed to let the system is more robust and stable in positioning. The developed robust control architecture consists of three components: 1) sliding mode controller, 2) adaptive law, and 3) force allocation. From the provided experimental results, satisfactory performances of the hereby developed system, including stiffness and precision, have been successfully demonstrated.