In this study, thermally induced changes in the surface of a thin gold film deposited on Si(100) with a 5 nm thick titanium adhesion layer were investigated. The analysis involved X-ray photoelectron spectroscopy, low-energy electron diffraction, and scanning tunnelling microscopy. The sample was subjected to stepwise annealing under ultra-high vacuum conditions at temperatures ranging from 430 to 1330 K. Low-temperature annealing up to 450 K did not alter the morphology but improved the cleanliness of the gold film surface. Annealing between 530 and 930 K resulted in the disintegration of the gold film, along with mixing and interaction between the sample components. Annealing the sample at 980 K led to the emergence of a gold silicide surface on Si(100) exhibiting the (5 × 3.2)R5.7° reconstruction.