A showcase assembly unit for the showcase structure is disclosed, which includes a roller support frame and a plurality of parallel sets of rollers mounted on the roller support frame, wherein the rollers in each set of rollers are mounted rotatably and arranged one after another from the rear end toward the front end of the roller support frame, and a plurality of individual articles, such as canned foods or drinks, may be placed across two or more parallel sets of rollers and are capable of moving one by one from the rear end toward the front end of the roller support frame. In the showcase assembly unit for the showcase structure according to the present invention, each roller has a specific width that is smaller than the size of the bottom of a particular article across the roller, and each of the rollers in each set is axially offset relative to each of the rollers in each adjacent set.