The present invention provides a compound having melanocortin receptor agonist activity or antagonist activity, which is a novel biaryl compound represented by the formula (I): wherein ring A and ring B are optionally further substituted 6-membered aromatic rings; X is —CONR4—, —SO2NR4—, —CH2NR4— (R4 is a hydrogen atom, an optionally substituted hydrocarbon group, etc.), etc.; Y is a spacer having 1 to 12 atoms, etc.; Z is —CONR6—, —CO— (R6 is a hydrogen atom, an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group), etc.; R1 is an optionally substituted amino group, etc.; R2 is an optionally substituted hydrocarbon group, etc.; R3 is an optionally substituted hydrocarbon group, etc.; and R5 is an optionally substituted hydrocarbon group, etc.; or a salt thereof.