International audienceMicropositioning systems are widely used in many applications, for example, optical industry, medical devices, and micro-assembly applications. Commonly, MEMS-based micropositioning systems use conventional fabrication techniques such as lithography, etching, and thin-film processes. However, a typical microfabrication process by using the masking and etching operations is limited to fabricate a 3-dimensional complex device. This research presents a novel design of a 3D micropositioning system with electrostatic comb drives with a converting mechanism. The device can convert the in-plane motion to the out-of-plane displacement. The proposed model is possible by using FEMTOPRINT ® machine which combines material modification by femtosecond laser-beam and chemical wet etching. The results from the simulation shown that the 3Dcomplex micropositioning system can achieve a wide range of workspace up to 1,212.79 μm 2 . In X-axis and Z-axis, it can translate up to a maximum displacement of 33.34 μm and 75.14 μm respectively, while the footprint of the device is 1.65×1.10 mm 2 . This device can be a new prototype of MEMS based-micropositioning system named “glassy MEMS” that is suitable for a 3D-complex mechanism and can be used in many applications