A review is presented of the data available in the literature on the thermodynamic properties and structure of gaseous metaborates studied by high-temperature mass spectrometry, gas-phase electron diffraction, spectroscopy, and quantum-chemical methods. The reliability and inconsistency of the thermodynamic properties and structural data obtained by these methods for gaseous metaborates are discussed. The specific features of the application of the above methods for investigating the thermodynamic properties and structure of gaseous metaborates at high temperatures are analyzed.