A combined holding cabinet comprises a first holding box and a second holding box.The first holding box system has a first top plate, a first bottom plate and a first side plate group. The first top plate, the first bottom plate and the first side plate group form a first holding space, and the first top plate is provided with a plurality of first protruding parts to form a first wave structure.The second holding box is stacked on the first holding box, and has a second top plate, a second bottom plate and a second side plate group. The second top plate, the second bottom plate and the second side plate group form a second holding space, and the second bottom plate is provided with a plurality of second projections to form a second wave structure.The first wave structure and the second wave structure are in contact with each other, so that the second protrusions and the first protrusions interfere with each other.一種組合容置櫃，係包含一第一容置箱以及一第二容置箱。第一容置箱係具有一第一頂板、一第一底板與一第一側板組，第一頂板、第一底板與第一側板組係圍構出一第一容置空間，且第一頂板設有複數個第一凸出部以形成一第一波浪結構。第二容置箱係堆疊於第一容置箱上，並具有一第二頂板、一第二底板與一第二側板組，第二頂板、第二底板與第二側板組係圍構出一第二容置空間，且第二底板設有複數個第二凸出部以形成一第二波浪結構。第一波浪結構與第二波浪結構係彼此接觸，使該些第二凸出部與該些第一凸出部彼此干涉。
