NOVELTY - An electronic electroconductivity ceramic powder material is obtained by carrying out reduction processing of cubic system titanium oxide pyrochlore. The pyrochlore is a complex oxide of titania and rare earth element such as lutetium, ytterbium, thulium, erbium, holmium, yttrium, gadolinium, europium, samarium and/or cerium. The unfixed ratio amount of rare earth element in complex oxide is greater than 0 and less than 0.5.    USE - For cubic system titanium oxide pyrochlore sintered compact used as anode of electrolysis tank (all claimed) used as electrolytic cell for sulfur cycle hybrid hydrogen production.    ADVANTAGE - The inexpensive electronic electroconductivity ceramic powder material has high corrosion resistance, conductivity and catalytic activity. The electrolysis tank obtained using the sintered compact as anode, has improved durability and favorable over-voltage reduction during electrolysis.    DETAILED DESCRIPTION - An electronic electroconductivity ceramic powder material is obtained by carrying out reduction processing of cubic system titanium oxide pyrochlore. The cubic system titanium oxide pyrochlore is a complex oxide of formula: RE2-xTi2O7-~d, and has rare earth elements (RE) in A site. Element (RE) is lutetium, ytterbium, thulium, erbium, holmium, yttrium, scandium, dysprosium, terbium, gadolinium, europium, samarium and/or cerium. The unfixed ratio amount (x) of element (RE) is greater than 0 and less than 0.5.    INDEPENDENT CLAIMS are included for the following:    (1) cubic system titanium oxide pyrochlore sintered compact, which is obtained by sintering the electronic electroconductivity ceramic powder material, and carrying out reduction processing; and    (2) electrolysis tank for sulfur cycle hybrid hydrogen production, which has an anode comprising the electronic electroconductivity ceramic powder material.    DESCRIPTION OF DRAWING(S) - The graph shows the relationship between electroconductivity and A site non-stoichiometry of cubic system titanium oxide pyrochlore used for electronic electroconductivity ceramic powder material. (Drawing includes non-English language text).