In the display device according to the present disclosure, a linear operation mode, in which an image is changed by tracing an operation surface substantially along a straight line, and a circular-arc operation mode, in which an image is changed by tracing the operation surface substantially along a circular arc, are set as operation modes for changing images displayed on the operation surface by tracing an operation surface of a touch panel. A CPU extracts the characteristic manner in which the operation surface is traced based on information acquired from the touch panel when the operation surface is being traced, decides which one of the linear operation mode and the circular-arc operation mode as the operation mode based on the extracted characteristics is the operation mode, and changes to the other operation mode in response to a change in the characteristic manner in which the operation surface is traced.