A transport device includes a traveling holding member which can travel while holding a storage container, and a move out prevention mechanism which prevents substrates from moving out of an opening of the storage container. The move out prevention mechanism is configured to include a contacting member which can be moved between a contact position at which the contacting member is in contact with side faces of the substrates, and a spaced apart position at which the contacting member is spaced apart from the side faces of the substrates. The contact position is set such that the contacting member is located between an opening side end portion and a central portion of the substrates in a direction along which the substrates are inserted and removed.