[en] An automatic station for measuring the beta total radioactivity of air has been designed. The station consists in an intake section with a capacity of 384 cubic metres of air a day and a glass fibre ribbon filter and in a detection section with three shielded Geiger counters, a plastic beta detector and a NaI (Tl) crystal detector. This stage is linked to the counting section that processes the data and outputs the values of the radioactivity minimum, mean and maximum. The minimum radioactivity measurable is almost 0.015 pC; for such a radioactivity the relative error is 45%. For the mean values the relative error amounts to almost 10%. This station is therefore particularly reliable for its high sensitivity and for the little relative error