A new apparatus for the measurement of 222Rn diffusion through shielding foils developed in the frame of the NEMO collaboration is briefly described. The setup is based on the electrostatic collection of radon progenies 218Po and 214Po. The NEMO project is an underground experiment for the study of double beta decay processes. For such type of experiments the efficient suppression of background caused by radon is essential. The first test of the apparatus has been carried out using Penefol foil (0.8 mm thickness) and the suppression factor of radon concentration has been obtained.