Static and dynamic dielectric properties of liquid ethanol have been studied as a function of the wave-vector number by computer simulation. Molecular dynamics simulations at room temperature have been performed using the optimized potentials for liquid simulations (OPLS) potential model proposed by Jorgensen [J. Phys. Chem. 90, 1276 (1986)]. The time dependent correlation functions of the longitudinal and transverse components of the dipole density as well as the individual and total dipole moment autocorrelation functions have been calculated. The infrared spectra and the dielectric relaxation of the liquid have been also analyzed. Results have been compared with the available experimental data. Special attention has been dedicated to investigate the molecular origin of the different analyzed properties.