A heat-curable fluoropolyether adhesive composition comprising (A) a linear polyfluoro compound having at least two alkenyl groups and a perfluoropolyether structure, (B) a fluorinated organohydrogensiloxane having at least two SiH groups, (C) a platinum group metal catalyst, (D) an organosiloxane having at least one SiH group and at least one epoxy and/or trialkoxysilyl group, and (E) a compound having at least two allyloxycarbonyl groups can be cured to metal and plastic substrates by heating at a temperature from 20° C. to less than 100° C.