Transport properties of semiconducting beta-FeSi2 thin films obtained by co-sputtering of iron and silicon and post-anneal are investigated. In these polycrystalline thin films, majority carriers are electrons and their Hall mobility can reach values of 900 cm(2)/Vs at room temperature. Conductivity,, Hall effect and photoconductivity of unintentionally doped silicide thin films are studied. The results obtained in two of them are presented, because they are representative of the extreme values found for the Hall concentration. They turn out to be, respectively, 1.8 X 10(17) and 6 X 10(15) electrons cm(-3) at room temperature. In addition to shallow donors present only in the first sample, deeper centers show ionization energy of 0.11 and 0.23 eV, respectively. For the second sample, the substrate contribution has to be considered for extracting values which are relevant for the beta-FeSi2 film alone. Photoconductivity takes place in these samples : at 80 K, it shows a maximum value at 0.86-0.87 eV, which correlates well with the direct band gap of beta-FeSi2 while at ambient temperature a step still appears at the same energy. Such results are a consequence of the important decrease of residual impurity concentration in comparison to values published previously.