A new meshing method is introduced to obtain a hexahedral mesh for three dimension MEMS models. MEMS models are built from 2 dimensional masks according to a process sequence. In most of cases, it leads to layered geometries, whose faces are parallel to the z axis or the (x,y) plane. This paper describes a new algorithm to create two and a half dimension(2.5D) hexahedral meshes for these layered models. By the method, the quadrilateral meshs in the (x,y) plane are generated and hexahedral elements are created by extending these quadrangles along z axis. Compared with popular Sweeping algorithm, it is faster and simpler to generate a hexahedral mesh. The mesh size is the only parameter to input before meshing and it spends less than 10 s for the mesh with 10 000 hexahedron elements, which is 10 to 1 000 times faster than that of the Sweeping method. Meanwhile, it can generate a MEMS model according to fabrication processes, which creates an easy way from 2 dimensional mask to 3 dimensional mesh.