To provide a method of manufacturing a unit muntin for a lattice assembly having a novel constitution which enables also formation of a lattice assembly structure shaped like a completely closed circle, by forming the muntin (component for realizing a lattice of the lattice assembly structure) indispensable for the traditional lattice assembly structure by a new manufacturing method which has not been adopted heretofore, and to provide the lattice assembly structure constituted of a novel structure using the muntin.

In the method of manufacturing the unit muntin for the lattice assembly, muntin materials 10 are temporarily fitted and fixed in linear disposition. An imaginary central point is set at a place located on lines intersecting the muntin materials 10 perpendicularly and spaced therefrom at a prescribed distance and regulation is made so that the direction being always in contact with an imaginary circumference around the imaginary central point be the direction of cutting the materials. Then, the muntin materials 10 temporarily fitted and put in the fixed state are cut sequentially by an appropriate means so that the cuts being deep at about a half of the longitudinal size of the materials are formed, and thereby the unit muntin 1 is formed.