A container body 1 for accommodating a multiple number of precision substrates in alignment, a door element for opening and closing the open front of container body 1 and a multiple number of positioning parts 40 arranged on the bottom of container body 1 are provided. Each positioning part 40 is formed as a concave portion with a pair of parallel ribs 2 formed on the bottom surface of container body 1 and inner surfaces 9 of curved portions 8 of a track 6 formed in a bottom plate 4. Inner surfaces 9 of track 6 are formed to be inclined linearly becoming gradually wider downwards from their top while the upper ends of inner surfaces 9 are extended to an opposing area 2a located between the lower ends of paired parallel ribs 2.