To provided an azo pigment which has extremely excellent dispersibility and dispersion stability and exhibits good color hue and high tinting strength, preferably, an azo pigment which has a length in a long axis direction of 0.01-30 m when observed under a transmission microscope.

The azo pigment or a tautomer of the same is represented by formula (1) which exhibits characteristic X-ray diffraction peaks at Bragg angles (20.2) of (i) 7.6 and 25.6, (ii) 7.0, 26.4, and 27.3, or (iii) 6.4, 26.4, and 27.2 in X-ray diffraction with characteristic CuK line.