A glass substrate transport box which is easy to handle and transported and adapted to protect glass substrates is provided at drastically reduced production cost. At least the body of the box is a molded piece of resin foam with a foaming ratio of 3-30, e.g. polyolefin foam, which has grooves for supporting glass substrates on at least a pair of its opposed inside walls. Preferably the inside wall of the body has a relatively dense skin layer. The resin foam may contain an electrically conductive polymer or an antistatic agent.