Provided are a 4-[5-(pyridine-4-yl)-1H-1,2,4-triazole-3-yl]pyridine-2-carbonitrile crystalline polymorph, which is useful as a pharmaceutical product, and a production method therefor. The present invention relates to a 4-[5-(pyridine-4-yl)-1H-1,2,4-triazole-3-yl]pyridine-2-carbonitrile crystalline polymorph, and three different crystalline forms are obtained by purification via a salt, storage under humidified conditions or recrystallization.