This study included the IAQ survey concentrated on particle levels in the library store (area of 1000 m 2 and having books or journals over 100 000 pieces in total) at the basement. The store was divided into three sections covered with plastic walls. Each section was cleaned with three different methods: two vacuum cleaners equipped either by HEPA filters I or II and one cleaner equipped with a water filtration unit. In addition, the surfaces of all sections were swept by wet cloth after twelve hours of vacuum cleaning. The relative humidity and temperature were found to be nearly the same during three cleaning periods. Both wet and two dry cleaning methods were found to remove dust on surfaces similarly effective.