Disclosed is an apparatus for cleaning bottles made of synthetic resin so as to remove dust or impurities attached to the insides of the bottles by static electricity, in which air in an ionized state is changed into air in a neutral state and the neutr(lized air is injected into the bottles. Conventionally, a mechanism for cleaning the insides of bottles using compressed air has been mainly used. However, in this conventional system, since the compressed air in an ionized state such as cation and anion is supplied into the bottles, dust or impurities attached to the insides of bottles by static elasticity generated therein is electrically charged. Therefore, it is difficult to remove the electrically charged dust or impurities from the insides of bottles. Even though the dust or impurities are eliminated from the bottles by force, the eliminated dust or impurities blow away from the bottles and then are again blown into the bottles by an air flow or pressure difference generated by the flow of the compressed air injected into the bottles, thereby contaminating the bottles and degrading a cleaning effect of the apparatus. In the apparatus for cleaning bottles, air going through filtration and neutralization steps is supplied to clean the insides of bottles, impurities eliminated from the bottles after a cleaning step are separately collected to a collector so as to prevent them from being blown into the bottles, and the positions of the bottles are successively changed several times so as to effectively clean the bottles.