Abstract: Provided is a new use of Brown's gas, more particularly, to the use of Brown's gas for the treatment of diseases in mammals and a Brown's gas supply apparatus therefor. It is based on the assumption that the Brown's gas is a medium capable of directly supplying moisture (special form of water according to the third theory of Brown's gas) to many regions of the body via skin, etc. Various effects of the Brown's gas on the body have been demonstrated. In particular, provided is a new use of the Brown's gas for treatment or alleviation of the symptoms of a lesion in a lesional tissue, cell, or organ of a mammal. Provided is also a simple and inexpensive Brown's gas supply apparatus for supplying pure Brown's gas suitable to be applied to the human body.