An image forming apparatus that incorporates two job executing modes of: a. a usual mode for executing a job at a predetermined usual processing speed; and b. a quiet-sound mode for raising quietness during a time of executing a job by executing the job at a quiet-sound processing speed slower than the usual processing speed, the image forming apparatus comprising: a job executing portion that is configured to execute jobs of a plurality of kinds of functions including a scanning function, a printing function and a copying function, wherein the copying function is composed of the scanning function and the printing function, said job executing portion being configured to use the usual processing speed as a processing speed in the usual mode, and to use the quiet-sound processing speed as a processing speed in the quiet-sound mode; a mode setting portion that is configured to set in which one of the job executing modes of the usual mode and the quiet-sound mode to execute a job; and an operating portion that is configured to accept an operation for setting the job executing mode; wherein the operating portion is configured to accept a function unit setting operation for setting the job executing mode in a function unit; the mode setting portion is configured to set the job executing mode in the function unit based on the function unit setting operation accepted by the operating portion; and the job executing portion is configured to execute a job in the job executing mode set by the mode setting portion characterized in that, upon setting the job executing mode for the copying function, the operating portion is configured to accept the function unit setting operation for setting the job executing mode for the scanning function and the printing function separately. a. a usual mode for executing a job at a predetermined usual processing speed; and b. a quiet-sound mode for raising quietness during a time of executing a job by executing the job at a quiet-sound processing speed slower than the usual processing speed, a job executing portion that is configured to execute jobs of a plurality of kinds of functions including a scanning function, a printing function and a copying function, wherein the copying function is composed of the scanning function and the printing function, said job executing portion being configured to use the usual processing speed as a processing speed in the usual mode, and to use the quiet-sound processing speed as a processing speed in the quiet-sound mode; a mode setting portion that is configured to set in which one of the job executing modes of the usual mode and the quiet-sound mode to execute a job; and an operating portion that is configured to accept an operation for setting the job executing mode; wherein the operating portion is configured to accept a function unit setting operation for setting the job executing mode in a function unit; the mode setting portion is configured to set the job executing mode in the function unit based on the function unit setting operation accepted by the operating portion; and the job executing portion is configured to execute a job in the job executing mode set by the mode setting portion