A portable terminal provided with a text browser for perusing text contents which are supposed to be displayed on a display of the portable terminal, and a help browser for perusing help contents showing methods of utilizing the text contents. When a certain message is inputted from outside, it is determined whether the input message is a text message or a help message, according to which either the text browser or the help browser is activated. The help browser outputs the help contents through text, voice, static images, or moving images. The portable terminal sets each of a plurality of switch keys to an effective state or an ineffective state in accordance with the contents of the help contents. In setting certain switch keys to effective states, LEDs, etc. provided corresponding to those switch keys are lighted. When the rest of the switch keys are set to ineffective states and any operation by those switch keys are made ineffective, not only the operation by the user becomes simple, but also false operation can be prevented.