The utility model provides a steam box, which comprises a steam box cover and a plurality of layers of steam box lattices. The plurality of layers of the steam box lattices are stacked together. Carrying ledges are symmetrically fixed on the outer wall of the steam box lattices, wherein, the wall of each steam box lattice which is not arranged in the top layer comprises an inner wall and an outer wall. Air holes are uniformly arranged on the inner wall of each steam box lattice, a gap is arranged between the inner wall and the outer wall of each steam box lattice, and the inner wall and the outer wall of each steam box lattice is fixedly connected through a supporting rib. The wall of the steam box lattice arranged on the top layer has single layer, and the diameter of the steam box lattice arranged on the top layer is the same as the diameter of the outer wall of each steam box lattice which is not arranged on the top layer. When the utility model is in use, the steam not only can heat the food from the bottom of the steam box lattice, and can heat the food from the side faces from the gaps arranged between the inner walls and the outer walls though the air holes uniformly arranged on the inner walls. The utility model has the advantages of uniform heating of the food and high thermal efficiency.