The first part of this thesis investigates the establishment of a calibration procedure for the Nanoscope II Scanning Tunnelling Microscope (STM) based on the use of calibration standards, which have been certified by the National Institute of Standards and Technology (NIST). Two measurement techniques are compared. One involves taking a fast fourier transform (fft) of a surface profile, the resulting measurement corresponds to the period of the optimum frequency of the fft spectrum. In the other method the surface profile is differentiated and the measurement corresponds to separation of consecutive peaks on the differential curve. The second part focused on Scanning Tunnelling Spectroscopy (STS) measurements of the Au(l 11) surface in air and liquid environments. A characteristic I-V curve was obtained for the Au(lll) surface usmg current voltage(I-V) spectroscopy. The apparent tunnelling barrier height was calculated from current-distance (I-S) spectroscopy. For the Au(lll) surface imaged in Decalm a value of 1 4eV was calculated for the apparent barrier height, while for the same surface in a air value of 10 eY was calculated. The final part of this thesis involved a study of the native oxide and sulphur passivated InP(lOO) surfaces and preliminary measurements on Germanium surfaces X-ray photoemission spectroscopy(XPS) was used to determine the chemical composition of the InP surfaces STM images of the native oxides of InP(lOO) surfaces were found to have a root mean square (rms) roughness greater than that of the sulphur passivated surface I-V spectroscopy of both the native oxide and sulphur passivated InP(lOO) displayed characteristics similar to those observed for corresponding treatments to the GaAs surface I-S spectroscopy of the native oxide on InP(lOO) gave a apparent barrier height of 0 3 eV, while for the sulphur passivated InP(lOO) surface the value was 0 05 eV The very low apparent barrier height on the passivated surface was attributed to the effects of tip induced band bending. Further STS studies of the native oxides on Ge(l 11) surface and hydrogen passivation of that surface display the same trends as observed on InP(lOO).