A device control method used in a device control system in which an operation terminal is used to remotely operate a device with a server device mediating between the operation terminal and the device, the device control method including: acquiring, upon reception of an operation instruction for operation of the device from the operation terminal, environment information pertaining to at least one of the device and the operation terminal; performing a determination of whether or not to cause execution of processing corresponding to the operation instruction based on whether or not the environment information satisfies a predetermined condition; and causing the device to execute an execution command for execution of the processing when a result of the determination is affirmative, and not causing the device to execute the execution command when the result of the determination is negative.