The physical parameters of Tau Cet are analyzed based on new and high-quality data. The effective temperature is determined to be 5250 + or - 50 K. The discrepancy of the abundance inferred from the Fe I lines with the lowest excitation cannot be explained by errors either in atomic or stellar parameters and implies the need for models incorporating non-LTE and/or a more reliable UV opacity. The obtained abundances for the alpha-particle elements exceed that of the Fe group by 0.2 dex, in complete agreement with previous results for metal-poor dwarfs of the Galactic disk population. The microturbulence value is found to be 1.1 + or - 0.1 km/s. The surface gravity value is determined to be 1.0 + or - 0.3 solar mass.