ILET(ionic liquid electrospray thruster), one of the electrostatic micro-thrusters, has recently become a hot topic for researchers. The emitter is the core component that significantly affects the thruster performance, so its manufacturing is considered as one of the key technologies for the ILET development. Combined with the operating principle and the development history of ILET, the characteristics of propellant transport and manufacturing requirements for all three types of emitters, namely capillary, externally-fed and porous emitters, were analyzed. Based on this, the typical manufacturing materials and related manufacturing technologies were reviewed, while the advantages and disadvantages of different manufacturing technologies such as ion etching were summarized and remarked. For the proven manufacturing method of ultrafast laser ablation based on porous material, the development suggestions including emitter design, novel material fabrication, and study on laser-matter interaction mechanism were given.