We address an eective application of spoken dialogue interface by combining with virtual space technologies. Virtual space enables us to do what cannot be done in the real world with feeling as if doing in the real world. Spoken dialogue systems are to realize our intention by understanding expressions that include concept and a nuance. We clarified advantages and disadvantages of speech interface in a multi-modal virtual space, then designed a virtual fitting room, where the speech interface works effectively and the dialogue is enhanced by multi-modal interaction. The system supposes that a user is in a fitting room. The user can select his favorite clothes interactively by stating his preference and checking the virtual mirror. It was observed that the combination of spoken language input and virtually-real image output realizes a natural and robust interaction, thus giving better user satisfaction than conventional platforms.