Diagnostics of plasma of a flare on radiation in MM and ultra-violet ranges

Solar flares are a phenomenon of extreme development of solar activity. They are a consequent of development of a broad spectrum of the physical processes happening in active area. The description of these processes is the important astrophysical problem. Radio-astronomical observations of solar flares help to understand essence of happening events more deeply. The important key for their understanding is diagnostics of a state of medium of flare. Its state can be characterized key parameters. It is temperature of plasma of flare in a pulsing phase of its development, an electron concentration, quantity of a magnetic field and the plasma parameter showing the relation of gas and magnetic pressures. The special role in definition of parameters of medium is played with radio-astronomical observations in mm range. On these waves the area of flare is optically thin and observable radiation immediately is connected to a nucleus of area of flare.