The first Russian advanced infrared (IR) atmospheric sounder IKFS-2 was launched in July 2014 on the "Meteor-M" No. 2 meteorological satellite. It is planned that this instrument and similar devices will continue to operate until 2025 aboard the current and subsequent satellites of "Meteor-M" series. IKFS-2 is a Fourier transform spectrometer covering the spectral domain of 5-15 mu m. It belongs to a class of hyper-spectral IR sounders, designed to measure the outgoing IR radiance spectra and to provide information on the thermodynamic parameters and the composition of the atmosphere such as vertical temperature and humidity profiles, estimates of the ozone and other trace gases total column amounts. In the paper, the IKFS-2 operation on board "Meteor-M" No. 2 is analyzed, including the assessment of the measurements' quality (the errors of radiometric and spectral calibration) and their information content. Since launch, the instrument performance has been remained stable, and the actual IKFS-2 characteristics (threshold value of NESR, uncertainty of onboard radiometric and spectral calibrations, spectral resolution) meet the planned requirements. There is a good agreement between IKFS-2 measurements and measurements of independent satellite instruments (SEVIRI, IASI). The paper also provides an overview of the developed scientific basis for simulation and interpretation ("inversion") of satellite measurements. The examples of output IKFS-2 level 2 products (vertical profiles of temperature and humidity, total ozone content) are given together with the error analysis. The performance of atmospheric (temperature and humidity) profile retrievals and the feasibility of total ozone content estimates are evaluated by comparison with independent ground-based or satellite measurements. (C) 2019 The Authors. Published by Elsevier Ltd.