Substrate processing apparatus

There is provided a substrate processing apparatus including: a transfer region communicating with a process chamber where substrates are processed; a first shelf region installed above the transfer region and having a first shelf storing transfer vessels accommodating the substrates; a second shelf region installed below a stage part where the vessels to be transferred to and from an external device are loaded, and having a second shelf stacking and storing the transfer vessels; and a transfer vessel transfer robot installed inside a housing accommodating the transfer region, the first shelf region and the second shelf region and transferring the vessels to and from the stage part, the first shelf, the second shelf, and the transfer region. The transfer vessel transfer robot includes: a main body base part; a first table part; a first driving part; a second table part; a second driving part; and a vessel support part.