A substrate processing system is provided. The substrate processing system includes: a first transfer apparatus; at least two first accommodating units including an upper first accommodating unit and a lower first accommodating unit; multiple first substrate processing units, which are divided into at least a first group and a second group and arranged in a height direction; an upper second accommodating unit corresponding to the first group; an upper second transfer apparatus corresponding to the first group; a lower second accommodating unit corresponding to the second group; a lower second transfer apparatus corresponding to the second group; a first delivery apparatus corresponding to the first group; and a second delivery apparatus corresponding to the second group.