The purpose of this study was to evaluate indoor air pollutants of children’s facilities in libraries. The indoor pollutants, which were managed under the “Indoor Air Quality Control Standards” and “Environmental Safety Standards for Children’s Activity Zones,” were measured within five months. The new environmental pollutants such as phthalates and pesticides were also measured. The pollutant-measuring device was installed in children’s spaces in libraries and children’s libraries of the metropols. The result of investigating indoor pollutants showed that the concentration of fungus and floating bacteria had low distributions due to the use of air purifiers in all libraries. The concentration of HCHO and TVOCs was also measured lower than the environmental standards in well-ventilated libraries. On the other hand, phthalates and pesticides were detected in all libraries. In the case of heavy metals, they were mainly found in the finishing materials of the library walls and floors. As a result, indoor pollutants are managed under court receivership. On the other hand, phthalates and pesticides, which are not regulated by environmental standards should be managed because they were detected in all libraries.