A scheduling method for a substrate treating apparatus having a plurality of treating units for treating substrates, wherein, based on a procedure including a plurality of treating steps, a controller determines an order of treating a plurality of lots successively in the treating units. The method includes a step of preparing a plurality of schedules through execution of a basic allocating method, based on a systematic chart representing combinations of the treating steps for the respective lots, for allocating a first treating step of one of the lots, and thereafter, while following the systematic chart from the treating step, for searching and allocating as a next treating step a treating step selected from among succeeding treating steps in the lots, whose preceding treating step has an earliest expected completion time of all preceding treating steps; and a first allocating method for allocating treating steps based on the basic allocating method, and when a waiting time occurring with one of the treating steps exceeds an allowed time for enabling a standby at one of the treating units, for avoiding allocation of the one of the treating steps and restarting a search at one branching point before a branching point upstream of the one of said treating steps. The method further includes a step of selecting one schedule having been completed within a specified time, from the plurality of schedules prepared.