This work will cover to a standard method in monitoring silver nanoparticles in inhalation chambers for inhalation toxicity on experimental animals. More detailed defining of the scope will be discussed in the following specific items. 1) System set-up: Following equipments are interconnected : silver nanoparticle generator, inhalation exposure chambers, mass flow controller (MFC), Differential mobility analyzer (DMA) or Scanning mobility particle sizer (SMPS), Condensation particle counter (CPC), dilutor, filter, vacuum pump 2) Transmission electron microscopy to measure particle diameter and dispersion Particle concentration (number, mass, surface area) measurement in inhalation chambers by DMA or SMPS.