Abstract: A storage container for receiving precision substrates such as wafers, having increased strength and improved drying ability when washed. The storage container has a letter L-shaped circumferential wall (12) projectingly provided on an outer wall face, the circumferential wall functioning as a gasket insertion groove (12a). A first flange (13) horizontally extending from the lower end face of the letter L-shaped circumferential wall (12) and a second flange (14) horizontally extending from a position 10-30 mm lower than the first flange are respectively formed integrally with the container. Vertical ribs (15) are formed between the lower face of the first flange (13) and the upper face of the second flange (14).