The surface morphologies of thin gold films thermally evaporated on glass, mica, CaF2 and Si substrates were investigated by scanning tunneling microscopy (STM) and compared to each other. The surface roughness of the gold films and average area of the grains observed was investigated as a function of the temperature and length of time of prebake of the substrates. The dependence of the gold surface roughness on substrate temperature is discussed. For substrates held at room temperature the ionic interaction between gold particles and substrate surface determines the size of the grains. Large flat areas of dimensions of the order of 200 X 200 nm(2) are obtained for 80 nm thick films grown on glass heated at 300 degrees C for 6 h and areas flat over a macroscopic distance greater than 500 nm are obtained on mica heated at 400 degrees C for the same period of time. For CaF2 gold epitaxial growth starts to occur above 200 degrees C. Epitaxial growth of fee metals on alkaline halides is discussed.