Described herein is a technique capable of optimizing a timing of a maintenance process. According to one aspect of the technique of the present disclosure, there is provided a method of manufacturing a semiconductor device including: (a) transferring a substrate to a process chamber, and performing a substrate processing; (b) receiving maintenance reservation information of the process chamber wherein a maintenance timing at which the process chamber enters into a maintenance enable state is determined by the maintenance reservation information; and (c) continuously performing the substrate processing after the maintenance reservation information is received in (b) until the substrate processing in the process chamber related to the maintenance reservation information is completed, stopping one or more substrates including the substrate from being transferred into the process chamber, and thereafter setting the process chamber to the maintenance enable state.