Accompanied by the increases of vacant houses all over Japan, some support facility for children or elderly have been opened by utilizing existing buildings. Childcare support facilities reusing vacant houses for infants and the parents are increased since started “TSUDOI NO HIROBA PROJECT” in 2002. However, there is no national grant for the renovation costs and no strict maintenance provisions, so renovation contents and maintenance standard are different between facilities. In particular, the facility converted the vacant house, it is necessary to consider the following three points. 1) Securing indoor area corresponding to the number of users, 2) Development of function as a childcare support facility in the renovation costs, 3) Safety measures for the step of the indoor.<br> This paper aims to clarify the relationship of the spatial composition and usage and to evaluate the space function of childcare support facilities converted a traditional timber house in Yamaguchi City, Yamaguchi Prefecture.<br> Investigation objects are four facilities, SHUPPOPPO, KIRA-KIRA, RA-RA-RA, and HIRA-HIRA, in Yamaguchi City. Observational research was conducted for four days in each facility's opening day, and the behaviors of staffs and users were recorded throughout the day.<br> The findings obtained are as follows.<br> The playroom where users stay in mainly is ensured one-room space by the removal of existing fixture and partition wall. Dynamic or static playroom can be secured according to the age of infants by setting the main use of each four tatami-mat space. When there are many users, stay space of indoor is insufficient. Therefore, it's possible to expand playroom area by arranging the outdoor playground and wood deck which available from indoor.<br> At lunch time, playroom has been converted into the lunch space by clean up toys and placement table. It is important toy area, washroom and luggage area for the smooth preparation before lunch.<br> It is valid to set a tea room or a staff room at a dining kitchen or a dining. By this, interchange is promoted with other mothers or staffs while watching their infant. This can be evaluated as a usage setting utilizing a traditional timber house with an existing kitchen. Snack and tea space is also the same as lunch. Meanwhile, it's possible to cafe without disturbing the play of infants in playroom in the case of using the tea room.<br> For difference in level between playroom and entrance, safety measures have been taken by closing the existing fixture and installing the fence, and watching by staffs and parents.<br> Since the hand wash basin uses existing sinks or kitchen sinks, it cannot cope with simultaneous use at lunch, snacks, tea time. Although it is desirable that the hand washing basin is prepared in priority, it is sometimes difficult to add facilities requiring space. In that case, it is conceivable that the staff guides users by voice communication or the preparation time for lunch and snacks can be extended according to the number of users.