Report-no: FM 98-11; version 2.3 (18 May 1999) Author: Giovanni Gallavotti Title: Statistical Mechanics. A short treatise. Abstract: this is a preprint of a book: I welcome comments and critiques. Please send them to the address below. The book consists of 359 pp. The file is one single postscript file, gzipped. 882 Kb. The book has been published by Springer Verlag, ans I warmly thank them for allowing that it remains here for personal consultation and downloading. For information about the copyrights please contact Springer Verlag directly. Keywords: Statistical Mechanics Giovanni Gallavotti Fisica, Universita' di Roma La Sapienza, P.le Moro 2, 00185, Roma, Italia.