Extraterrestrial microparticles have been collected and investigated for more than a century. Recent developments of analytical techniques and mass collecting methods have brought us three types of collections and new knowledge of cosmic dust; (1) the smallest size group (smaller than 100μm) from the Stratosphere mainly consisting of the most primitive and fragile particles, most of which are unmelted porous aggregates of fine grains thought to be typical of interplanetary dust particles (IDPs) or cometary debris just falling onto the earth, (2) the largest size group (several 10 μm to several mm) from deep sea sediments, the best known cosmic dust collection as "cosmic spherules", all of which melted during atmospheric entry and were heavily weathered during their terrestrial ages, and (3) the medium size group (several μm to several 100μm) from the Polar ice/ snow mainly consisting of partially melted and unmelted particles distinct from conventional chon- dritic materials. Although quantity of a single particle is too small, compiled information obtained by the various new methods will give us a new horizon of material science of the extraterrestrial matter.