A machining oil applying apparatus that applies machining oil onto a thin metal plate that is being conveyed toward a press apparatus includes: an upper surface applying unit that is impregnated with machining oil, contacts an upper surface of the thin plate and applies the machining oil onto the upper surface; a lower surface applying unit that is impregnated with the machining oil, contacts an lower surface of the thin plate and applies the machining oil onto the lower surface; and an applying unit moving portion that causes the upper surface applying unit and the lower surface applying unit to move reciprocally in a direction perpendicular to a conveying direction of the thin plate, wherein the upper surface applying unit and the lower surface applying unit always move in respectively opposite directions perpendicular to the conveying direction.