Abstract: The present invention solves such a problem that a scroll parameter did not fit in with an operator intuition. A scroll controlling program is stored in the HDD 12. The scroll controlling program controls a CPU 14 to function as a controller that changes a scroll parameter (a scroll initial velocity Vs0 and a scroll duration T) in response to contact coordinate data outputted before termination of the contact with a touch panel 24. In this scroll controlling program, the scroll initial velocity Vs0 is defined by an operation expression “Vs0=F(Vtc)” using a change rate Vtc of the contact coordinate as a variable. In contrast, the scroll duration T is defined by an operation expression “T=G(L)” using a change amount L of the contact coordinate as a variable.