The thermoelectric power and d.c. conductivity of Mn/SiOx thin films containing 10 at.% Mn have been measured between 278 and 578 K as a function of substrate temperature (293-418 K). Thermoelectric gower and d.c. electrical conductivity measurements suggest that over the temperature range 278-500 K, conduction is due to delocalised electrons at the Fermi level and electrons in donar localised states. For temperatures above 500 K, hole conduction takes place via extended states.