In an information device, a fingerprint image capture section captures a fingerprint image of an operator. When a fingerprint image captured by the fingerprint image capture section is referred to as a first fingerprint image and a fingerprint image captured at a given time interval after the first fingerprint image is captured is referred to as a second fingerprint image, a comparison section compares minutiae points of the first and second fingerprint images extracted by a minutiae point extraction section. An image generation section generates image information which is changed while reflecting the comparison results of the comparison section. A display section displays an image based on the image information generated by the image generation section. The information device may be provided with a check section, and display control by the display section may be performed after a fingerprint image is checked by the check section.