A steel sheet heating method that heats a steel sheet (K) to be pressed before hot press molding includes: bringing the steel sheet into a heating furnace (10) including a heater (15) on an inside surface of the heating furnace in a state where the steel sheet is supported in a vertical direction while an unnecessary portion of the steel sheet that becomes unnecessary after molding is fixedly supported by a support member (30); and performing heating at a prescribed temperature in the heating furnace, then taking the steel sheet out of the heating furnace, and after that cutting and removing the unnecessary portion before hot press molding or during hot press molding.