To provide a cleaning agent for pretreatment to hot dip plating which can improve operational environment at a low energy cost without using lead, and in which liquid management is easily performed, and which has a reduced number of stages and a long liquid life, with which industrial waste can be reduced, and which has high cleaning effect as well, to provide a pretreatment method using the same, and to provide a hot dip plating method.

The cleaning agent for pretreatment to hot dip plating is an aqueous solution or emulsion comprising an inorganic electrolyte, an oily substance, and an organic acid or the salt thereof. In the pretreatment method to hot dip plating, a metal is dipped into the cleaning agent prior to hot dip plating. In the hot dip plating method, a metal is dipped into the cleaning agent, the metal is water-washed and dried, and the metal is dipped into a plating bath to apply plating to the surface of the metal.