Provided is an authentication apparatus that, in case of showing an inputted password as an unrecognizable state, shows it a recognizable state with maintaining confidentiality according to operation by a user. The password inputted by the user is shown on a password input area as the unrecognizable state, such as “*.” While a password peripheral region is pushed by the user along with a password input area, a control part changes the password from the unrecognizable state, where a displaying condition of the password shown on password viewing area being hidden by “*,” into the recognizable state, and the inputted password itself are shown.