Provided are a melt-blown nonwoven fabric including fibers containing a cyclic olefinic resin, and a production method thereof. The melt-blown nonwoven fabric includes fibers containing a cyclic olefinic resin. The melt-blown nonwoven fabric includes fibers containing a cyclic olefinic resin, wherein, among fiber diameter data at 100 points that are randomly selected from a scanning electron microscope (SEM) image taken in a magnification of 1,000, and ordered from a smallest fiber diameter to a largest fiber diameter and divided into quartiles, an average value of fiber diameter data having a larger than a third quartile is equal to or less than 30 µm.