Abstract: Denitration catalyst unit, comprising two or more platy catalyst elements, wherein the platy catalyst element has an edge located on gas-inflow side, an edge located on gas-outflow side and edges located on either side of the platy catalyst element, the platy catalyst elements are piled so as to align the edges located on gas-inflow side and the edges located on either side of the platy catalyst elements respectively, each of the platy catalyst elements alternately has more than one flat part in the shape of a flat plate and more than one concavo-convex part in the shape of platy convex strips on the upper and lower surfaces, the platy convex strips are parallel to one another and are obliquely disposed at an angle ? of not less than 50° and not more than 85° to an extending direction of the edge located on gas-inflow side of the platy catalyst element so that a ridge of the platy convex strip on the upper surface of one of the platy catalyst elements intersects with a ridge of the platy convex strip on the l

Abstract: It is an object to provide a regenerated denitration catalyst whose denitration performance is restored compared with a denitration catalyst before use, utilizing a spent denitration catalyst, and a method for manufacturing the same. In a regenerated denitration catalyst according to the present disclosure, a spent denitration catalyst including a first titanium oxide as a main component, and a second titanium oxide are mixed. The spent denitration catalyst is already used in a denitration reaction in which nitrogen oxides in a gas are decomposed into nitrogen and water using a reducing agent. The second titanium oxide has a larger specific surface area per unit weight than the first titanium oxide. A content of the second titanium oxide based on a total weight of the first titanium oxide and the second titanium oxide is preferably 10% by weight or more and 90% by weight or less.