An image processing device includes a touch sensor and a controller. When an operation in which two icons including a function selection icon and a detailed setting selection icon are simultaneously pressed is received in a reception screen, the controller sequentially switches a setting value of a detailed setting corresponding to the pressed detailed setting selection icon at regular predetermined intervals and changes an image displayed in a preview area to a processed image on which the function has been executed at the switched-to setting value, while the simultaneous pressing operation is continued on the two icons.