The study for the first time presents a method for producing indium-gallium-zinc oxide InGaZn2O5 using the nitrate-tartrate complex decomposition method. The material is characterized by X-ray diffraction, electron microscopy, IR- and UV-spectroscopy. It has been established that the use of tartaric acid as a precursor already at a temperature of 500 °C leads to the formation of a single-phase homogeneous material consisting of nanocrystalline particles in the form of micrometer agglomerates. The proposed method for producing nanoparticles can be used in the future to produce semiconductor inks based on IGZO.