One of the way in which annual maintenance is improved is to support with wearable devices connected with network. Two basic key systems for advanced plant maintenance using Head Mounted Display(HMD) have been developed, which are ¡Èa communication support system between a foreman and workers¡É and ¡Èa remote cooperative system utilizing gazing point information¡É. The one enables a foreman to observe and instruct plural workers at the same time. And the other realizes a supporting function from a remote expert. The effectiveness of these prototype systems have been confirmed by basic laboratory experiments in the university.