The portable terminal includes a display unit configured to display a screen; a first buffer and a second buffer configured to sequentially store display data for the displayed screen; a first determination unit configured to determine whether to perform single-buffer control or double-buffer control based on update data for the displayed screen; and a setting unit configured to set, if single-buffer control is appropriate, a display control method of the display unit to a display control method using the first buffer and to set, if double-buffer control is appropriate, a display control method of the display unit to a display control method using the first buffer and the second buffer.