Abstract: Provided is a pretreatment method for rubber, which, in the pyrolysis treatment for used rubber, can reduce the odor during pyrolysis, effectively reduce the sulfur and/or nitrogen content in the resulting pyrolysis products, which is particularly easy to volatilize, and further reduce the odor of the oil obtained from the pyrolysis. This pretreatment method for rubber is a pretreatment method for rubber, in which sulfur crosslinked rubber is pretreated prior to pyrolysis treatment, characterized in that: the method includes a holding process in which the sulfur crosslinked rubber is held for minutes or longer under conditions satisfying the prescribed formulas (1) and (2) to obtain pretreated rubber; and that in the holding process, when the ambient pressure P is atmospheric pressure, the holding is performed under an air flow of inert gas.