The Submillimetron is the international project of the space telescope for full sky survey in submillimeter region 0.15-1.5 mm using facilities of the Russian segment of the International Space Station (ISS). A free flying module for the project is under development in corporation Energia. Periodic docking of the module to the ISS gives possibility to combine low cost with reliability, refilling, repairment and maintenance. The concept of the telescope combines a 0.6 m mirror cooled to liquid helium temperature with a novel type of microbolometers arrays developed at Chalmers University (Sweden). This combination gives unique possibility to realize background limited sensitivity about 10-18 W/Hz-1/2 in the spectral minimum of the extraterrestrial background near frequency 1 THz between peaks of galactic dust emission and CMB. The angular resolution of the instrument is about 1 arcmin, field of view ~1°.