To provide a packaging case which is equipped with a cushioning function and which is fabricated from a flattened shape and workability for storing an inner case into an outer case is improved and surely prevents breakage and deformation of the inner case.

The packaging case is formed of a tray-shaped outer case (1), an inner case (2) to be housed in the outer case (1) with its upside opened in a manner the same as the outer case, a bottom cushion plate (4) to be interposed at least between the inner case (2) and the bottom of the outer case (1) and an outer cover (3) for covering the outer case (1) in a manner of capping. The inner case (2) is in a structure wherein an article housing space (C) thereof is surrounded with cushioning side walls (E) each of which is in a double structure having a cushioning space (D) formed therein and easily erected and folded down. Each of the cushioning side walls (E) is formed in a structure wherein an interior plate (21), a frame-forming plate (22), an exterior plate (23) and a fixing plate (24) are successively connected with creases to each of sides of an inner bottom 20, and a free end part (25) excluding a part corresponding to the frame-forming plate (22) of the fixing plate (24) is stuck to the back side of the inner bottom (20) so that the cushioning side walls (E) on four sides can be erected independently without being engaged with one another by conventional means of flap pieces (G) with the inside thereof overlapped with corners of a frame (F).