A mobile phone comprises a display, etc. If a camera function is performed, a through image (preview image) based on an imaging parameter value, a shutter key, etc. are displayed on the display. A RAM is registered in advance with imaging parameter value brought into correspondence to a coordinates range. When a predetermined time period elapses after a touch operation is made to the shutter key, an auxiliary key corresponding to the coordinates range is displayed. If a user moves a finger into the coordinates range based on the displaying of the auxiliary key, a current imaging parameter value is changed to a registered imaging parameter value. If the finger is released in such a state, an image imaged based on a changed imaging parameter value.