Success of a product is determined by the market. I am therefore very pleased that the ?rst two editions of this book have been sold out, and that the publisher has asked me to work on a third, revised and expanded edition. - viously,thereisstilldemandfor¿MatterandMethodsatLowTemperatures¿, even almost 15 years after publication of the ?rst edition. Before working on this revision, I had written to more than 20 expert colleagues to ask for their recommendations for revisions. Besides details, the essence of their response was the following (1) Essentially, leave as it is; (2) AddmoreinformationonpropertiesofmaterialsatT> 1K;(3)Addinfor- tion on suppliers of low-temperature equipment. Besides following the latter tworecommendations,Ihave,ofcourse,takenintoaccountallrelevantnew- formation and new developments that have become available since the second edition was written more than 10 years ago, in 1995. I have found this inf- mation in particular in the journals ¿Journal of Low Temperature Physics¿, ¿Review of Scienti?c Instruments¿, and ¿Cryogenics¿, as well as in the P- ceedingsoftheInternationalConferencesonLowTemperaturePhysics,which took place in Prague (1996), Helsinki (1999), Hiroshima (2002), and Orlando, FL (2005), as well as of the International Symposium on Quantum Fluids and Solids, which took place in Ithaca, NY (1995), Paris (1997), Amherst, MA (1998), Minneapolis, MN (2000), Konstanz (2001), Albuquerque, NM (2003), and Trento (2004); the latter proceedings have also been published as issues of the Journal of Low Temperature Physics.