To provide a low-cost and free-assembling multistage thin-box-shape rack capable of arranging and storing thin-box-shape materials by arbitrarily increasing the number of rack plates as necessary in an installation space occupied by a single rack and storing several types of different-size thin-box-shape materials.

This multistage thin-box-shape rack is provided with the multiple same-shape and same-size rack plates 1 mutually oppositely disposed parallel, and front/rear independent connecting pieces 2 and 3 detachably connecting the front/rear four corners of the adjoining shelf plates 1 and 1 to one another. The central position of the rear-side independent connecting pieces 3 and 3 is accorded with the central extension line between the front-side independent connecting pieces 2 and 2 on the shelf plate 1 and the inside distance (inner size) between the rear-side independent connecting piece 3 and the rear-side independent connecting piece 3 is set smaller than the inside distance (inner size) between the front-side independent connecting piece 2 and the front-side independent connecting piece 2. The several types of different-external-size independent connecting pieces 2 and 3 are prepared according to the sizes of several types of different-size thin-box-shape materials 5.