To improve the throughput of a substrate treating system.

In a substrate treating method in which untreated substrates W are sequentially taken out from cassettes, sequentially transported to a plurality of treatment units, and treated in parallel and, after treatment, treated wafers W are sequentially returned to the cassettes, the predicted treatment ending time of one lot of wafers W is calculated and displayed based on a treatment recipe set to a plurality of wafers W corresponding to at least one lot of wafers W (S85) and a cassette CR housing a plurality of untreated wafers W corresponding to one lot is accepted and another cassette CR housing a plurality of treated wafers W corresponding to one lot is delivered, based on the predicted treatment ending time (S89).