This study describes the design and performance of an ambient air sampler consisting of an Andersen cascade impactor using inertial filter technology (ANIF) as a supplemental stage to separate nano-particles smaller than 70 nm. The design of the inertial filter resulted in an aerodynamic cutoff size of dp50 ~70 nm, a satisfactory sharpness in classification and a separation behavior comparable to that of a previously reported nanosampler (NS). The pressure drop at the backup filter in the sampler was ~30 kPa at a flow rate of 28.3 L/min. The ANIF has a number of advantages over currently available samplers, such as LPI and nano-MOUDI, such as reducing the loss of semi-volatile components in ultrafine particles by evaporation at reduced pressures, as well as having a smaller initial cost for the equipment for nanoparticle collection. Furthermore, the size distribution of the ambient particles measured with the ANIF compared favorably with those measured by conventional instruments that are currently available on the market.