When predetermined information is input into an input field and an OK button is pressed on a user authentication screen displayed on a monitor screen by a browser at entry time, the input predetermined information, the input predetermined information, the positional information about the input field and the OK button, and the identification information on the user authentication screen are obtained by the input unit and entered in an external storage device through a storage unit. When the authentication screen detection unit detects the user authentication screen by the authentication screen detection unit at input time, the input/press unit automatically inputs the predetermined information read from the external storage device into the position of the input field obtained according to the positional information read from the external storage device through the storage unit, and the position of the OK button is automatically pressed.