Provided is a password authenticating apparatus that can provide a hint for selecting a password without displaying a part of the password. The input-receiving unit receives input of a password as an input password. A password-header-comparing unit compares a header portion of the input password up to a number of header comparison characters with authentication information, and determines whether or not the header portion of the input password up to the number of header comparison characters matches a portion from the start of a registered password up to the number of header comparison characters. A screen-generating unit, when it is determined there is no match, generates a header-error screen providing guidance that the input password already does not match in the header portion as a display screen. A display-control unit causes a display unit to display the display screen generated by the screen-generating unit.