Abstract: An apparatus is disclosed which can automatically load semiconductor wafers into a vertical type heat treatment furnace and unload treated semiconductor wafers out of the heat treatment furnace. The semiconductor wafer treating apparatus comprises exchange unit for exchanging the semiconductor wafers between the cassette and the wafer boat in a predetermined exchange position, transfer unit for allowing the wafer-held boat to be transported between the exchange position and a respective, vertical type heat treatment furnace and for allowing the transfer of the wafer boat to be effected between the transfer unit and the respective heat treatment furnace, and an elevator unit provided in the heat treatment furnace and adapted to receive the wafer boat from the transfer unit and to load the wafer boat into a vertically erect process tube and unload the wafer boat from the process tube.