MgO thin films were deposited on SiO2/Si(100) and coming 7059 glass substrates using bis(2,2,6,6-tetramethyl-3,5-heptanedionato) magnesium(II) as a precursor dissolved in a solvent by electrostatic spray deposition (ESD). The ESD method is a cheap deposition method and is suitable for large area deposition. When pure tetrahydrofuran (THF) was used as a solvent, a number of large particles appeared on the MgO thin film surface due to homogeneous nucleation. However, by adding l-butyl alcohol or 1-octyl alcohol to THF, homogeneous nucleation was restricted and the number density of the large particles was also drastically reduced. X-ray diffraction (XRD) analysis showed that the MgO films deposited at a substrate temperature of 673 K had a (100)-preferred orientation regardless of the type of solvents used. Characterization using Fourier Transformed-infrared (FT-IR) and spectroscopic photometer revealed that the crystallized MgO thin films on the glass substrate had a high optical transmittance (> 85%) in the visible range.