Transparent undoped semiconductor indium oxide ﬁlms were deposited by radio frequency (rf) plasma enhanced reactive thermalevaporation (rf-PERTE) of indium at low substrate temperature. It was experimentally veriﬁed that the variation of rf power densityhas a strong inﬂuence on the electrical and structural properties of the ﬁlms. The thickness of the InO x ﬁlms is of about 100 nm. Resultsshow that InO x ﬁlms show an average visible transmittance of about 85% and energy gap of about 2.6 eV. Structural and electrical conductivity measurements show that ﬁlms are polycrystalline and there exists a linear variation of conductivity logarithm vs reciprocal oftemperature. Electrical conductivity variation of 17.6 to 5.8 x 10-3 (Ω cm)-1 for ﬁlms produced at rf power densities ranging from 3.9 to78.1 mW cm-3 was obtained. This controllable semiconductor behavior can therefore satisfy the requirement of a particular applicationfor these type of ﬁlms.