To provide a rainfall bar instrument by which the force of the wind in the atmosphere and the rainfall can be controlled, suffocation caused by fire can be avoided by moving air by condensing vapor particles floating in the atmosphere along a laser beam bar instrument.

The vapor particles floating the atmosphere along a laser beam bar instrument B are set, that laser beam bar instrument B is fitted to a motor A and rotated so that the move of air (the wind) can occur. In this case, it is preferable to use the wavelength (1.064) of Na:YAG laser for setting the vapor particles.