Provided is an RPM control method for an inducer for a gas furnace that induces a flow of combustion gas produced in a burner from a heat exchanger to an exhaust pipe. The RPM control method for an inducer for a gas furnace includes: (a) initiating a heating operation for the gas furnace; (b) determining whether the operation time during which the heating operation is performed is equal to or longer than a first time period; (c) if it is determined that the operation time is equal to or longer than the first time period, detecting whether a pressure switch is turned OFF; and (d) if the pressure switch is detected as turned OFF, increasing the RPM of the inducer by a first value.