1. A scheduler for use in a substrate processing apparatus including a plurality of substrate processing sections for processing substrates, a transfer section for transferring the substrates, and a controller for controlling the substrate processing sections to process the substrates and controlling the transfer section to transfer the substrates, the scheduler being adapted to be incorporated in the controller for calculating a substrate transferring schedule, the scheduler comprising: a function to successively calculate substrate transferring schedules for substrates which are newly supplied to the substrate processing apparatus; a function, in an event of a fault occurring in the substrate processing apparatus and a state of the fault being taken as an initial state, to calculate the substrate transferring schedules which remove a substrate from one of the substrate processing sections which suffers the fault, and transfers the removed substrate to another one of the processing sections which is normal to continuously process the removed substrate, or retrieve the removed substrate and place it into a substrate cassette after the removed substrate is washed with water and dried; and a function to recalculate the substrate transferring schedules which makes the one of the substrate processing sections which suffers the fault unusable and supply new substrates to the substrate processing apparatus.