The growth characteristics and electrical properties of thin films of crystalline beryllium oxide (BeO) on Si (100) substrates grown using electron beam evaporation (EBE) are described. To expand the commercial viability of BeO, a combination of EBE with thermal oxidation was optimized to facilitate its use in nanoscale semiconductor devices. The surfaces of the EBE BeO films were found to be smooth with limited quantities of native oxides or metal silicates, as determined using atomic force measurements and X-ray photoelectron spectroscopy, respectively. Moreover, high-resolution transmission electron microscopy revealed that the films were highly crystalline. Excellent insulator properties, including a dielectric constant of 6.77 and a breakdown voltage of 8.3 MV/cm, were deduced from a series of capacitance-voltage and leakage current measurements. Reflection electron energy loss spectroscopy and ultraviolet photoelectron spectroscopy indicated that the films exhibited a high band gap of 8.6 eV and a high conduction band offset of 3.43 eV. Collectively, these results indicate that EBE BeO films hold promise for use as electrical insulators in Si CMOS and nanoscale device applications.