An operation displaying device including: an operation screen which receives an instruction for operation; a computing device which executes computation; and a performance monitoring unit which monitors a performance of an application software that executes display processing, wherein: when an operation mode of the operation displaying device is in a power saving mode and a remaining memory capacity of a memory, which is used as temporary storage by the computing device, is less than or equal to than a predetermined threshold, the performance monitoring unit restarts the application software which is running.