CuM_xAl_1-xO₂ (M=Mg, Sr, Ca, Ba, Zn and Cd) ceramics have been prepared using a solid phase reaction method. The phase identification during synthesis was investigated using X-ray diffraction measurement. The thermoelectric properties such as the Seebeck coefficient (S), electrical conductivity (σ) and thermal conductivity of the ceramics were evaluated after sintering at 1423 K for 2 h in air. The power factor, S²σ, of CuMg_0.005Al_0.995O₂ was approximately 1.6 × 10^-5 W/K²m over a wide range of temperature of 650 to 900 K, which was the highest among all specimens prepared, and the value was approximately twentyfold larger than the value of CuA1O₂.