This thesis concerned the development of a scanner system for use in the Terahertz region of the Electromagnetic spectrum. The approach used by the prototype developed, utilises two tilting mirrors for the purposes of scanning a target under investigation. An object is scanned by tilting an incident beam of radiation to a point of interest on the target, on this basis an image can be formed on a point by point basis. The Thesis begins with an Introduction to THz radiation and its associated properties. The need for a Terahertz scanner and the potential applications in the biomedical, security and space research are outlined. The reader is then introduced to various approaches utilised by currently existing scanners and the approach used for the work carried out in this thesis outlined in detail. The techniques used for computationally modelling diffraction limited optical systems are discussed namely Fresnel Diffraction, Gaussian Beam Mode Analysis (GBMA) and Physical Optics. The effectiveness of these techniques are highlighted by using each method to model elementary optical systems. The techniques are then used to computationally model the optical system used for the prototype developed and results presented. The final section is concerned with the development of the prototype including background theory on components used, implementation of the components and verification of alignment procedure. The development of the computer controlled tilting mirror system and its integration with the prototype is also outlined. Finally the results of the operational scanning prototype are presented and discussed.