The present invention relates to an azole compound represented by the formula [I] ##STR00001## wherein W is S or O; R is --COOR.sup.7, --X.sup.1-A.sup.1-COOR.sup.7 (R.sup.7 is H, alkyl) or tetrazolyl; R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are H and the like; A is --(CH.sub.2).sub.m--X-- (X is --N(R.sup.8)--, --C(R.sup.9)(R.sup.10)--, --CO-- or --CO--N(R.sup.8)--); B is aryl or aromatic heterocyclic group; R.sup.5 is H and the like; R.sup.6 is --(Y).sub.s1-(A.sup.2).sub.s-Z (Y is --O--, --S(O).sub.t--, --N(R.sup.13)--, --N(R.sup.14)--CO--, --N(R.sup.14)--SO.sub.2--, --SO.sub.2--N(R.sup.14)-- and the like, A.sup.2 is alkylene, and Z is cycloalkyl, aryl, aromatic heterocyclic group, indanyl, piperazinyl, a prodrug thereof or a pharmaceutically acceptable salt thereof. The compound [I] of the present invention has a protein tyrosine phosphatase 1B inhibitory activity, and is useful as a therapeutic agent for diabetes, a therapeutic drug for diabetic complications or a therapeutic drug for hyperlipidemia.