Abstract: Provided is an inorganic structure including a plurality of inorganic particles; and a binding part that covers a surface of each of the plurality of inorganic particles and binds each of the plurality of inorganic particles together. The binding part contains: an amorphous compound containing at least one of aluminum or titanium, oxygen, and one or more metallic elements; and a plurality of fine particles having an average particle size of 100 nm or less. The plurality of inorganic particles has an average particle size of 1 ?m or more, and the plurality of inorganic particles has a volume percentage of 30% or more.

Abstract: To provide a holder housing tool with high general-purpose properties and favorable usability, and a file including the holder housing tool. A holder housing tool includes a first restriction part and a second restriction part. The first restriction part is hooked on one edge portion of an opening part of a holder by being inserted into the opening part. The second restriction part restricts the position of the holder at a position where the first restriction part is hooked by coming into contact with the holder.