Background The unconstrained master devices have emerged as attractive alternatives to the existing linkage-based counterparts. However, the conventional unconstrained master device's manipulation methods have several disadvantages in efficiency and precision. Methods We propose an encountered-type master device based on an electromagnetic tracking solution with a prismatic joint at the tip, capable of continuous spatial manipulation with the tip supported on the surface. We performed path-following task and pointing tasks to analyze the performance of the master device. Results The most convenient, efficient, accurate positioning and precise pointing were possible with a closed loop support condition. Moreover, the tasks under this condition were also completed with higher accuracy, and precision when applying lower motion scale factors. Conclusions The proposed master device allowed precise and accurate manipulation for microsurgical tasks. Compared with the conventional unconstrained master devices, the proposed master device provides the ability to perform precise work with a clutching-free motion.