The objective of this study is to defines production space related to the functional shift of library space into third space. This study refers to the theory of Lefebvre (1991) on social practice. Space in Lefebvre's terminology is always a social space, so library space is assumed to be a social product. This study used ethnography with six digital native users as informants collected purposively. The data collection techniques were observation, interview, and literature study. The result showed that there was a functional shift in UGM library space which was initially only for studying, then they became third space. UGM library space as social space is inseparable from and always related to social realities around them. UGM library is an intellectual knowledge institution where library users interact in physical and virtual environments to expand learning and facilitate the creation of new knowledge. In this context, library space is produced in such a way to preserve the dominant, so a social space can only be produced through socio-historical relation. Third space is a space formed from reproduction space (living space) due to integration on the space experienced and understood. The layout practice in UGM Library space showed that digital native users used them for various things.