To break the vicious cycle of buying a nonuse adult desk instead of a presently using learning desk due to the growth of the body and the like, its conversion into a bulk waste, mass disposal and mass incineration.

A generation desk body is so formed that the inner part of a top board of a desk material is drawably inserted between the both side boards of bookcase materials to constitute a narrow width desk for elementary school/junior high school students with a small working plate closer to the bookcase materials by its depth by a simple reassembling; and a bookcase having an equal height to the height of the top board of the desk material is adjoinedly added thereto to constitute a wide width desk for high school/university students with a wide working plate. The bookcase materials and the desk material are so constituted as to be singularly usable as an independent bookcase and an independent desk. This generation desk body can be used in all the lifetime through his/her respective ages and can be used for multi-generations within the strength durability of the materials.