A throughput can be improved. A substrate processing apparatus includes processing units arranged in a vertical direction and configured to process substrates; and a substrate transfer device configured to be moved in the vertical direction and perform loading/unloading of the substrates into/from the processing units. Further, the substrate transfer device comprises a first transfer arm and a second transfer arm which are arranged in the vertical direction and configured to be moved in the vertical direction independently, and movement ranges of the first transfer arm and the second transfer arm in the vertical direction are overlapped with each other.