An object of the invention is to provide an inner fin for a tube used in an EGR cooler which promotes the heat exchange between exhaust gases and cooling fluid, which makes it difficult for the tube to be clogged with soot and which is easy to be assembled...

An object of the invention is to provide an EGR cooler which enhances a cooling performance by increasing a ratio of the volume of a core portion which performs a heat exchange and enhances a pressure resistance strength. There is provided an EGR cooler ha...