In an information processing device, when an operation button is pushed, a menu is displayed on the screen of an LCD. When the whole portable type information processing device (PDA) is rotated around the X-axis, the Y-axis or the Z-axis with the operation button being pushed, the rotation is detected by a triaxial gyro sensor, and on the basis of the detection result a cursor displayed on the screen is moved on the menu. By releasing the operation button when the cursor is located on a desired menu item, the selection of the menu item at which the cursor is located is settled, and the processing corresponding to the selected menu item is started.