This invention provides a lens for ultrasonic diagnosis apparatuses having requisite acoustic characteristics concerning sonic velocity, acoustic impedance and acoustic attenuation and exhibiting high abrasion resistance the lens including a base formed from a silicone rubber composition, and a urethane coat layer placed on an outer surface of the base, wherein the urethane coat layer includes 100 parts by mass of a urethane resin and 3-7 parts by mass of silica. This invention also provides a probe therefor having the same characteristics, including a case having at least one open end the lens arranged so that a tip thereof is exposed at the end a piezoelectric element housed in the case an acoustic matching layer placed between the lens and the element and a backing layer disposed opposite the acoustic matching layer with the element in between.
