The method is suggested and the experimental results are presented on the temperature determination of (CO2)(N) clusters (nanoparticles) (N >= 10(2) is a number of monomers in a cluster) in a beam using SF6 molecules from intersecting molecular beam as probe thermometers. The molecules are captured by clusters and, after a certain time, sublimate from the surface of clusters carrying information on the velocity and temperature (internal energy) of clusters. Using time-of-flight (TOF) method the kinetic energy (velocity) of sublimated SF6 molecules was measured and the temperature of clusters was determined to be T-cl = (105 +/- 15) K. (C) 2009 Elsevier B.V. All rights reserved.