An operating device for performing user authentication and controlling display of a screen, the operating device comprising: a user authentication unit configured to perform a fingerprint authentication operation by detecting an operation of pressing a user's finger on a fingerprint reading region in which fingerprint information of the user's finger is read, reading the fingerprint information of the user's finger and determining whether or not the read fingerprint information matches registered fingerprint information that is registered in advance; an icon acquisition unit configured, if the read fingerprint information matches the registered fingerprint information, to acquire icons (405; 500; 501; 603) indicating functions that can be used by the user of the read fingerprint information; an icon switching unit configured to determine whether or not the operation of pressing by the user's finger on the fingerprint reading region continues; wherein the icon switching unit is further configured, if the read fingerprint information matches the registered fingerprint information and the operation of pressing by the user's finger on the fingerprint reading region continues, to switch, every predetermined switching time, the acquired icons (405; 500; 501; 603) for display in a vicinity of the user's finger in order in which the icons (405; 500; 501; 603) are acquired, and the icon switching unit is further configured to time elapsed time since the start of the display of an acquired icon with a predetermined timer, to determine whether or not the elapsed time exceeds a preset switching time, and to erase the acquired icon (405; 500; 603) and display a subsequently-acquired icon (405; 501; 603) if the elapsed time exceeds the preset switching time; a function transition unit configured, if the press by the user's finger is released while the icons (405; 500; 501; 603) are switched for display, to perform transition to a function of an icon (405; 500; 501; 603) displayed at a time when the press by the user's finger is released, and a display reception unit configured, if the read fingerprint information matches the registered fingerprint information and the operation of pressing by the user's finger on the fingerprint reading region does not continue immediately after the fingerprint authentication operation, to display an initial screen that displays icons for respective various functions in a selectable manner, and when the user selects the icon for a predetermined function, to display an operation screen for the function corresponding to the selected icon. a user authentication unit configured to perform a fingerprint authentication operation by detecting an operation of pressing a user's finger on a fingerprint reading region in which fingerprint information of the user's finger is read, reading the fingerprint information of the user's finger and determining whether or not the read fingerprint information matches registered fingerprint information that is registered in advance; an icon acquisition unit configured, if the read fingerprint information matches the registered fingerprint information, to acquire icons (405; 500; 501; 603) indicating functions that can be used by the user of the read fingerprint information; an icon switching unit configured to determine whether or not the operation of pressing by the user's finger on the fingerprint reading region continues; wherein the icon switching unit is further configured, if the read fingerprint information matches the registered fingerprint information and the operation of pressing by the user's finger on the fingerprint reading region continues, to switch, every predetermined switching time, the acquired icons (405; 500; 501; 603) for display in a vicinity of the user's finger in order in which the icons (405; 500; 501; 603) are acquired, and the icon switching unit is further configured to time elapsed time since the start of the display of an acquired icon with a predetermined timer, to determine whether or not the elapsed time exceeds a preset switching time, and to erase the acquired icon (405; 500; 603) and display a subsequently-acquired icon (405; 501; 603) if the elapsed time exceeds the preset switching time; a function transition unit configured, if the press by the user's finger is released while the icons (405; 500; 501; 603) are switched for display, to perform transition to a function of an icon (405; 500; 501; 603) displayed at a time when the press by the user's finger is released, and a display reception unit configured, if the read fingerprint information matches the registered fingerprint information and the operation of pressing by the user's finger on the fingerprint reading region does not continue immediately after the fingerprint authentication operation, to display an initial screen that displays icons for respective various functions in a selectable manner, and when the user selects the icon for a predetermined function, to display an operation screen for the function corresponding to the selected icon.