The invention proposes a method and a device for needleless injection of liquid into a substrate, in particular of a liquid pharmaceutical or cosmetic preparation into a biological tissue, which allows a particularly fine liquid jet to be reliably injected completely into the substrate in a particularly advantageous manner. According to the invention, this is achieved by setting the ejected liquid jet in rotation about its jet axis before its impingement on the substrate, so that the jet receives a rotational movement and thus practically drills into the substrate without splashing away laterally.
