There is much interest in the development of field emitters for a number of applications, such as field emission displays and small x-ray sources. For these applications robust, sharp field emitters, capable of delivering suffi- cient current densities are needed. This thesis describes the development of an apparatus to test the field emission properties of a variety of sam- ples. This apparatus included a metal electrode to measure current-voltage characteristics, and a phosphor electrode to determine distribution and uni- formity of emission. Results are presented from a variety of zinc oxide (ZnO) nanostructures (grown by vapour phase transport, chemical bath, and pulsed laser deposition), and zirconium alloy films. The samples were analysed by a variety of techniques such as scanning electron microscopy and x-ray diffrac- tion, and their field emission properties determined using the field emission apparatus developed. A new treatment for analysing field emission results was developed and applied to the data. The results of these analyses were evaluated in the context of the current literature. The suitability of the aforementioned growth methods for growing ZnO nanostructures for field emission applications was investigated. The effect of inter-rod spacing and aluminium doping on the field emission properties of ZnO nanostructures was also investigated.