A systematic analysis, as complete as possible, of early type standard stars has been undertaken at the Astronomical Observatory of Trieste, in order to obtain a sequence of carefully determined spectroscopic data to be used in the comparison of “normal” and “chemically peculiar” stars. As an intermediate and necessary step, effective temperatures are derived. The determination of Teff is performed either by comparing observed and computed flux distributions, or by using a calibration of UV-visual photometric index versus Teff. The results for a sample of stars in the spectral type range B2-F8 are presented, and an analysis of the influence of the adopted value of log g on the derived Teff values is reported. As a check on the validity of the results, the Teff and log g values are used to construct a synthetic spectrum which is compared with the IUE high resolution observations of the stars in our list.