A wafer storage container has a container body and a lid. The container body has lid support inserts in a lid receptacle, and the lid has corner inserts for contact with the lid support inserts to support the lid. A supporting member is attached to the container body. The supporting member includes a base plate portion, side plates extending from the base plate portion, and a handle on each side plate for lifting the container body. The thin plate supporting member has contacting portions to support the thin plates, supporting members which elastically support the contacting portions, and a base support bar to support the supporting portions. The tip end of each supporting portion contacts a support stage, and elastically supports the contacting portions from both sides.