The utility model discloses a tool box, comprising a base, an inner layer, an upper cap and knobs. The tool box is orderly inserted with the base, the upper cap and the first, the second and the third through hole arranged on the two sides of the inner layer through the knobs provided with a convex part. A pushing block is arranged on the inside diameter of the second through hole of the upper cap, a second concave part is arranged on the inside diameter of the third through hole of the inner layer, and the convex part of the knobs is engaged with the second concave part of the third through hole. The convex part is pushed by the pushing block when the upper cap is lifted in order to drive the inner layer to be indirectly lifted, and the inner layer is indirectly pushed by the force of the entirety of the upper cap; compared with the existing tools box which only utilizes the convex part, the utility model has the better holding power. The concealed convex part and the concave part of the utility model can not be exposed; compared with the exposed structure of the existing tool box, the structure of the utility model is fine and shapely, and a hollow setting groove is arranged in the inner layer. The tool box can be used to hold a connecting rod, the hollow setting groove which has the clamping function is easily taken out, and the connecting rod can be observed through the hollow setting groove; besides, the tool box is provided with the ideal application effect.