A vane segment includes a blade ring, a plurality of vanes, and a caulking member. The blade ring includes a blade ring groove and a storage space forming portion. The blade ring groove includes a convex portion projecting from a second groove side surface of the blade ring groove to the first side. The storage space forming portion, in combination with an outer shroud, forms a storage space into which the caulking member enters. The caulking member is accommodated within the storage space, contacts with the blade ring groove and the outer shroud, and is exposed from an inner opening of the storage space.