Patent ID: 8731701

Claim:
A method of treating plural substrates using a substrate treatment apparatus that operates based on instructions received from a control unit, the method comprising: initiating the method of treating plural substrates using the substrate treatment apparatus; transferring each substrate of a plurality of substrates contained in a plurality of cassettes arranged on a plurality of mounting parts into a substrate treatment part, which contains a plurality of substrate treatment units for treating each substrate, transferring each substrate to and between each of the substrate treatment units; after treatment begins on each substrate, the control unit arbitrarily selecting a cassette from the plurality of cassettes and designating the selected cassette as a transfer-destination cassette to the substrate treatment apparatus for transfer of a designated substrate after completion of treatment for each substrate, the designating of the transfer-destination cassette occurring when a number of remaining treatment steps for the substrate reaches a predetermined set number; outputting an alarm signal from the substrate treatment apparatus to the control unit, if the designating of the transfer-destination cassette for each substrate has not been completed when the number of remaining treatment steps for each substrate reaches another number smaller than the predetermined set number; and based on the alarm signal and on a priority basis, the control unit designating the transfer-destination cassette for any substrates of the plurality of cassettes not already having a transfer-destination cassette; and after the completion of treatment, transferring each substrate into the plurality of cassettes mounted on the plurality of mounting parts and out of the substrate treatment part which includes transferring the designated substrates from the substrate treatment part respectively into the transfer-destination cassettes mounted on the plurality of mounting parts.