Abstract: A device for the sterilization of a dental, medical or similar instrument comprising a chamber (4), preferably frusto-conical in shape or downward tapering, with two walls (1, 2) separated by a hollow space, subdivided along axis into smaller spaces (3', 3", 3'", 3""), connected to the interior of the chamber by rings of holes (5', 5", 5'", 5"") with downward pointing jets, and passing at a distance (e) from the axis (K) of the chamber (4). These jets sterilize the entire internal and external surface area of the instrument along it length. The pressure upstream of the holes (5', 5", 5'", 5""), their diameter and direction, ensures that the lower and more contaminated part of the instrument is more thoroughly treated.