Spacer for furnace brazing having low wettability coating thereon

A spacer for brazing having a main body made of a steel plate such as a hot rolled steel plate, a stainless steel plate or the like and a coating provided on the surfaces of the main body by a flame spraying process such as a metal spraying process or a plasma spraying process. The coating is an inorganic substance which is low in wettability in relation to a brazing filler metal. When the brazing filler metal is a copper series one, the inorganic substance is a metal oxide such as a lumina, zirconia, a mixture of zirconia and titania, magnesium zirconate or the like, or an inorganic nitride such as boron nitride or the like.