Over the past decades, female labor force participation in Japan has continued to expand, accompanied by an improvement in daycare accessibility. This paper quantifies the daycare effects on employment of mothers with preschool children, analyzing newly constructed municipality-level data covering 1,758 municipalities for 2000, 2005, and 2010. The results suggest that 5%-11% of the increase in maternal employment rate during 2000 to 2010 was attributable to the improvement in daycare accessibility. However, the daycare effects on maternal employment are quite limited compared with those on enrollments at licensed daycare centers. Our new evidence suggests that such discrepancy could emanate from the fact that better access to licensed daycare centers encouraged working mothers to switch from kindergartens.