The SILAR method is a quick, affordable, and efficient way to create semiconducting thin films. However, when done by hand, producing the thin film with SILAR is laborious and time-consuming, and there is a high chance of human error. A completely automated SILAR unit prototype was developed using an open-source Arduino platform, and the parameters, such as the dipping time, cycle count, number of beakers, and substrate size, can all be altered as per the user needs. Using this automated SILAR unit, the Cu9Fe9S16 (a derivative of CuFeS2) thin films are fabricated and their structural, compositional, morphological, optical, and functional group properties are studied. The structural analysis indicated the formation of Cu9Fe9S16 with a grain size ranging from 11 nm to 21 nm. The micro-Raman analysis confirmed the formation of Cu9Fe9S16, and the morphological and elemental analysis of the thin films were also studied. The FTIR analysis indicated the formation of metal-sulfur bonds in the 561 cm−1 range. The optical analysis of the prepared thin film samples indicated that the Cu9Fe9S16 has a direct band gap in the range of 3.35 eV to 3.75 eV due to the quantum confinement effect.