Search for magnetic monopoles with the MACRO detector

Massive rare particles have been searched for in the penetrating cosmic radiation using the MACRO apparatus at the Gran Sasso National Laboratories. Liquid scintillators, streamer tubes and nuclear track detectors have been used to search for magnetic monopoles (MMs). Based on no observation of such signals, stringent flux limits are established for MMs as slow as a few 10(-5)c. The methods based on the scintillator and on the nuclear track subdetectors were also applied to search for nuclearites. Preliminary results of the searches for charged Q-balls are also presented.