Bulk CuAlO2 compound has been widely studied as a p-type metal oxide semiconductor material due to the simplicity in its synthesis and use of inexpensive raw materials. The Fe doping in CuAlO2 has been demonstrated to enhance the electrical conductivity. An in-depth analysis of the effect of Fe doping in CuAlO2 on the carrier concentration improvement was revealed. Delafossite CuAl1-xFexO2 powders with x = 0.00, 0.05, 0.10, 0.15, 0.20 and 0.30 were synthesized by a solid-state reaction method. The X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) studies were used to measure the atomic-ion concentrations and the oxidation state of each element. The variations of carrier concentration corresponded with a ratio of Cu2+/Cu1+ in CuAlO2. We found that the increase of Cu2+ /Cu1+ was caused by double effects through divalent metal ions (Fe2+) doping and excess oxygen (O2-delta) in CuAlO2. The maximum carrier concentration of 8.09 x 10(17) cm(-3) was obtained for the CuAlO2 sample at Fe content of 10 at.%.