To provide a small box packing machine which can surely pack paper to be packed even when it is relatively thick together with a product in a small box by solving the problem that a conventional small box packing machine employs paper about 3 mm thick to be packed in a small box which is sturdy and scratches a product when the paper is folded and results in a difficulty in packing the paper with the product.

This small box packing machine 1 for packing paper W with a product P in a small box B is provided with a pre-folding mechanism 2 for creasing in a fixed manner the paper W to be supplied and with a product pushing mechanism 3 for pushing the product P and the paper W into the box B.