To provide a new method for manufacturing bamboo laminated lumber, which is intended as a construction material, a vehicular material, and a furniture material etc. and is manufactured from a raw material made by processing bamboo to have a cross section of a fixed size, under present circumstances in which it is hard to obtain naturally growing bamboo having a material of a fixed size, in which it is difficult to utilize bamboo as it is due to differences in size and thickness, curvature and flatness of the material, etc., and in which utilization of bamboo in advanced countries has declined and bamboo is seldom used.

Round bamboo is subjected to a cutting process in a fiber direction to have a fixed width in order to obtain rod-like split bamboo, which is processed so that its one face has a flat plane and so that two inclined planes form a fixed angle with a flat-surface from both end faces in a width direction of the flat plane toward an inner side, and thereby a rod-like bamboo material is produced. The inclined planes are joined together and glued to be laminated in order to compose bamboo laminated lumber having a rod-like shape with a polygonal cross section or a tubular shape. Further, bamboo laminated lumber having a cross section of a fixed size is provided that is composed by using the bamboo laminated lumber having the rod-like shape or the tubular shape as a base unit and integrating a plurality of the base units.