ELECTRO-CHEMICAL REACTION UNIT, ELECTRO-CHEMICAL REACTION CELL STACK, AND ELECTRO-CHEMICAL REACTION UNIT PRODUCTION METHOD

An electrochemical reaction unit includes a unit cell including an electrolyte layer, and a cathode and an anode which face each other in a first direction with the electrolyte layer intervening therebetween, and one or a plurality of structural members. The electrochemical reaction unit further includes a glass seal member which contains glass and is in contact with two members facing each other in the first direction, the two members being selected from the unit cell and the one or the plurality of structural members. The glass seal member contains a plurality of crystal grains each having a ratio of a vertical dimension in the first direction to a horizontal dimension in a second direction orthogonal to the first direction of 1.5 or more.