Several Indium Phosphide based surface micromachining processes are presented in this paper, in order to develop Micro-Opto-Electro-Mechanical systems. By fabricating micro cantilevers composed of InP/Air gap pairs, the major techniques of the surface micromachining are studied, including non-selective and selective etching, rinsing and drying and so on. A severe problem of the sticking phenomena during the rinsing and drying is avoided by implementation of the Critical Point Drying (CPD) method.