The present invention provides a substrate processing apparatus which can restrain the extension of a transfer chamber caused by the heat and a manufacturing metohd of a semiconductor device. The substrate processing apparatus includes: a process chamber configured to process a substrate,a shaft installed in a transfer chamber, a substrate mounting stand connected to the shaft and including a heating part, a first thermal insulation part installed in a wall of the transfer chamber at a side of the process chamber, and a second thermal insulation part installed in the shaft at a side of the substrate mounting stand.