Transition metal dichalcogenides (TMDC) – MX2 (MoS2, WSe2, WS2, MoSe2, etc.) are layered two-dimensional graphene-like semiconductors with unique optical and electrical properties. Monolayers of TMDC have direct band gap in the visible frequency range and high mobility of charge carriers. Therefore, they are promising class of atomically thin semiconductors for a new generation of electronic and optoelectronic devices.  Generation of terahertz (THz) emission by TMDC‘s crystals surface is a new trend in THz technology, such studies just started to appear in last few years [1,2]. WSe2 as well as MoS2 is an attractive material in THz technology due to its optical and electronical properties. Previously, monolayer WSe2 hadn‘t been used as a source of THz radiation, thus the research is relevant.  Studied material was monolayer film WSe2 grown on a SiO2/Si substrate by technique of chemical vapor deposition (CVD). The oxide thickness was 285 nm. The film‘s quality was confirmed by methods of optical microscopy and photoluminescence spectroscopy.  In this work we present experimental results of studying of monolayer‘s WSe2 surface THz emission. Experiment was carried out by technique of THz time-domain spectroscopy. Time and spectral characteristics of the generated THz signals were obtained. We also demonstrate THz radiation dependence on the azimuthal angle. In addition, azimuthal dependences of second harmonic generation (SHG) and generated THz signals were compared. Azimuthal studies have shown that the sample is isotropic. Using COMSOL Multiphysics software, we have analyzed the density energy distribution in monolayer WSe2 as a function of a thickness of the oxide SiO2.  In conclusion, we can say that the mechanism of THz radiation is the built-in field, because the signals obtained from sample have an isotropic character. Our results provide a better understanding of light-matter interaction for monolayer WSe2.