NOVELTY - An azo compound is new.    USE - As an azo dye (claimed) for dyeing textile fibers (e.g. cotton, wool, or synthetic fiber), leather, paper, plastic, fur; for food, for hair dye, for an ink, for inkjet printing, for laser printing, for copying, for image formation by heat-sensitive transfer system, for an optical recording material, for an organic electroluminescent light-emitting material, for laser, for an organic semiconductor, for a solar cell, for a fluorescent probe, for a nonlinear optical material, for various filters for a solid state pickup tube, or for a display (e.g. a color liquid crystal display). Also as a pigment and a coloring agent.    ADVANTAGE - The azo compound has excellent fastness properties to heat, light, and the like, sufficient dyeing properties, and transfer-migration properties, while having clearness and high color density, and a high spectral absorption coefficient.    DETAILED DESCRIPTION - An azo compound of formula (I) is new.    Z1=a group of atoms necessary for forming an aromatic ring or an aromatic hetero ring;    Z2=a group of atoms necessary for forming an aromatic hetero ring;    V1 and V2=a substituent on the aromatic ring or the aromatic hetero ring formed by Z1 or Z2;    r and s=0-3;    R=coupler component (preferably a group of formula (ia) to (ig), R10-CH(Y1)-C(O)-NH-R11, R10-CH(Y1)-C(O)-o-R11, R10-CH(Y1)-C(O)-R11 or R10-CH(Y1)-R12;    X1=C or N;    Y1=a binding site to the azo group;    R6 to R9, R15 and R20 to R22=H or substituent;    W1=C or N;    R10=acyl, cyano, nitro, aryl, heterocyclic group, alkoxycarbonyl, aryloxycarbonyl, carbamoyl, sulfamoyl, alkylsulfonyl, or arylsulfonyl;    R11=alkyl, aryl or heterocyclic group;    R12=aryl or heterocyclic group;    R13=cyano, carbamoyl, alkoxycarbonyl, acylamino, arylamino, alkoxy, aryloxy or alkyl;    R14=phenyl (optionally substituted by at least one halo, alkyl, cyano, alkoxy, alkoxycarbonyl or acylamino);    Q1=a group of nonmetal atoms necessary for forming of a 5-membered azole ring containing 2 to 4 nitrogen atoms.    The group R is bonded with the azo group through a carbon atom. The groups R6 to R9 optionally bonded with each other to form a condensed ring. Provided that:    (1) R, V1 and V2 do not include any of carboxyl, sulfo or quaternary ammonium group;    (2) when W1 is C, then n is 1;    (3) when W1 is N, then n is 0.