A heat exchanger, for motorcycle use and mounted on a motorcycle and in which heat is exchanged between air and a heating medium flowing inside the heat exchanger, is characterized in that: the heat exchanger is fixed to a motorcycle body via a bracket 8; the bracket 8 includes a through-hole 80 into which a portion of the motorcycle body is inserted via a cylindrical grommet 9 and collar 10 capable of being elastically deformed; a cylindrical burring portion 81, which protrudes onto one side, is formed in an inner circumferential edge portion 80a of the through-hole 80; the grommet 9 is inserted into the through-hole 80 so that the grommet 9 can be contacted with the inner circumferential edge portion 80a of the through-hole 80; and a forward end portion of the burring portion 81 is directed outside in the radial direction with respect to the inner circumferential edge portion 80a of the through-hole 80.