To provide a compound which can be used as a stabilizer for a perfluoropolyether fluid which can be actuated at a temperature which is higher than 200°C and/or in the presence of a metal and/or in the presence of a Lewis acid.

This compound comprises a (per)fluoropolyether chain represented by the formula: T1-CFW1-O-Rf-CFW2-T2, and a terminal group having a heteroaromatic structure. In the above-noted formula, T1, T2, W1, W2 and Rf have the following meanings. T1 and T2 respectively have any one of F, CF3, C2F5, (C2F4)Cl and -CH2-B-Y, and -CH(CF3)O-Y [wherein B represents any one of O and S; Y represents a group represented by formula 1: (Q represents any one of O, S and -CH=N- group; and R1, R2, R3 and R4 respectively represent any one of H, a linear or branched 1-8C perfluoroalkyl group, NO2, and CN); and at least one of T1 and T2 which are the above-noted 2 terminal groups resperents -CH2-B-Y or -CH(CF3)O-Y and is a substituent comprising a ring having a heterocyclic structure]. W1 and W2 respectively represent -F or -CF3. Rf represents a (per)fluoropolyoxyalkylene chain having a number average molecular weight of in the range from 500 to 10,000.