ELECTROCHEMICAL REACTION UNIT, ELECTROCHEMICAL REACTION CELL STACK, AND PRODUCTION METHOD FOR ELECTROCHEMICAL REACTION UNIT

An electrochemical reaction unit including a unit cell including an electrolyte layer, and a cathode and an anode that face each other in a first direction with the electrolyte layer intervening therebetween; and a felt member containing a ceramic material or a metal and a silica component. The felt member includes both a first crystal structure and a second crystal structure, which is an SiOcrystal structure. Also disclosed is an electrochemical reaction cell stack including a plurality of electrochemical reaction units disposed in the first direction, at least one of the electrochemical reaction units being the above-described unit. Yet further disclosed is a method for producing the electrochemical reaction unit.