To conduct attendance and absence management for a user by authenticating the user using an image forming device.

The image forming device having an operation panel has a data input picture display means displaying a picture used for inputting data specifying the predetermined user and its authentication data by the user on the operation panel; a user authentication means authenticating the user based on the data specifying the user inputted by the user and its authentication data; and a clock-in/clock-out input picture display means displaying a clock-in/clock-out input picture inputting the clock-in or clock-out of the predetermined user on the operation panel.