Abstract: A boat includes a boat body, a top plate mounted on one end and a bottom plate mounted on the other end of the boat body. The boat body has a prop section and the prop section has a plurality of support portions provided parallel to each other along its longitudinal direction and each having a substantially circular arc-like configuration. The support portion has an opening at a front side to allow the forward end of an arm to be entered into an inside of the support portion to transfer a wafer W. Another opening is provided in a back section of a prop section at an area corresponding to the opening to allow the forward end of the arm to extend through it. The support portion supports the wafer W with the wafer edge portion set on its rest surface. The support portion and its rest surface are so formed as to have a substantially circular arc-configuration. By doing so, the rest surface of the support portion supports the wafer edge portion over as greater a length as possible.