Abstract: A reducing agent for use in production of a product gas containing carbon monoxide, the reducing agent being brought into contact with a raw material gas containing carbon dioxide to reduce the carbon dioxide to produce the product gas; the reducing agent containing a composite metal oxide represented by Ce1-x(M)xOy, where M is a metal element with an ionic radius smaller than an ionic radius of Ce with an identical valence number and an identical coordination number, x represents a positive real number, and y represents a real number from 1 to 4. The reducing agent that has a high conversion efficiency of carbon dioxide to carbon monoxide, and can be used, for example, in a chemical looping method, and a method for producing a gas using such a reducing agent.

Abstract: A suction-and-holding face for a component in a suction nozzle is formed from a semiconductor ceramic so that the suction-and-holding face to be brought into direct contact with the component in suction and holding has the characteristics of a semiconductor. Thus, detrimental effects due to static electricity on the suction nozzle as well as detrimental effects due to electrical conduction between the suction nozzle and the component can be prevented from occurring.

Abstract: A suction-and-holding face (14) for a component (1) in a suction nozzle (3) is formed from a semiconductor ceramic so that the suction-and-holding face to be brought into direct contact with the component in suction and holding has characteristics as semiconductor. Thus, detrimental effects due to occurrence of static electricity on the suction nozzle as well as detrimental effects due to an electrical conduction state between the suction nozzle and the component can be prevented from occurring.