An ink jet ink contains at least a coloring material and a specific water-soluble organic solvent and has both excellent color developability and excellent humidity resistance. The coloring material exhibits a small (9 or less) color difference ΔE value which is determined by a method including a series of specific steps and is represented as the square root of (L1−L2)2+(a1−a2)2+(b1−b2)2. The specific water-soluble organic solvent has an evaporation rate X smaller than that of water and a moisture absorptivity Y, the values of X and Y satisfying the relation of Y≦2.8X+10. The content of the specific water-soluble organic solvent is 50 mass % or more of the total amount of water-soluble organic solvents contained in the ink.