The operations, the states, and a positional coordinate where a finger or a pen touches on the touch panel are transmitted to the system controller 50 through an internal bus, and the system controller 50 determines an operation which has been performed on the touch panel based on the supplied information. As for Touch-Move, a sift direction of a finger or a pen which moves on the touch panel may be determined for each vertical component and each horizontal component on the touch panel based on a change of a positional coordinate. A series of operations from detection of Touch-On to quick Touch-Up without Touch-Move is referred to as a tap, and an operation of performing a tap operation twice is referred to as double-tap. Furthermore, an operation of performing Touch-UP after Touch-Down with certain Touch-Move interposed therebetween is referred to as rendering of a stroke. An operation of quick rendering of a stroke is referred to as a flick. The term “flick” means an operation of quickly moving a finger on the touch panel by a certain distance while the finger touches the touch panel and then separating the finger from the touch panel. That is, the term “flick” is an operation of quickly sliding the finger on the touch panel as a flip. When Touch-Up is detected immediately after Touch-Move by a predetermined distance or more at a predetermined speed or more is detected, it may be determined that flick is performed. Furthermore, if Touch-Move by a predetermined distance or more at a predetermined speed or less is detected, it is determined that drug is performed. The touch panel may employ any one of various methods including a resistance film method, an electrostatic capacitance method, a surface acoustic wave method, an infrared method, an electromagnetic induction method, an image recognition method, and an optical sensor method. The various methods further include a method for detecting a touch when contact with the touch panel is detected and a method for detecting a touch when a finger or a pen approaches the touch panel, and any one of the methods may be employed.