It is intended to provide a method for efficiently producing a diacylglycerol-rich fat andor oil that has a low content of trans-unsaturated fatty acids and has a good color and a good flavor characteristic to diacylglycerols. In the ink tank for the ink jet recording device having the ink storage section made of a plastic, the ink storage section has a coating layer including a liquid retaining member capable of retaining ink on an inner surface or an outer surface thereof. There is also a method of fracturing a subterranean formation. Each photograph is divided into sectors and digital Fourier transforms are performed on each sector. Laying of panels continues according to this process until the complete floor assembly has been laid.