According to the present invention, an arbitrary active constituent is sprayed stably so as to treat a target space. A method of the present invention, for treating a target space, includes the step of spraying, in the target space, a composition in an effective amount, the composition containing (i) a solvent and (ii) an electrolyte having a pK of not less than −10 but not more than 7, which pK is a dissociation constant with respect to water, the composition being sprayed as liquid particles in a mist form, which liquid particle have (I) an average particle diameter of not less than 100 nm but not more than 10 μm and (II) an average charge number of not less than +40 but not more than +40000.
