FIELD: medicine.SUBSTANCE: invention relates to medical equipment, namely to disposable automatic lancets. A lancet contains a case, a needle core and a spring. The needle core is provided with a needle body with a needle tip. The case forms an ejection chamber, in which the needle core is located. The needle core has one end, provided with a protective rod, and another end, fixed with the spring, with the protective rod having one end, originating from a needle ejection hole, and another end, connected with the needle core in a detachable way. The case has an elastic lever, extending into the ejection chamber, for blocking the needle core a bayonet clip, corresponding to the elastic lever end is provided on the needle core, with the end of the elastic lever being fixed with the bayonet clip. The case is provided with a start button, which contains two pairs of pressure projections, with each pair of pressure projections including the first pressure projection and the second pressure projection, with the pairs of pressure projections being placed into the ejection chamber, and in the ready state the first distance between each second pressure projection and the needle tip is shorter than the second distance between each first pressure projection and the needle tip. Each first pressure projection is near or contacts with the end of the elastic lever, and each second pressure projection is provided with a cog, with a self-blocking hook, corresponding to it, being provided on the case. The self-blocking hook is located on the pressure way of the cog, when each second pressure projection together with the cog, provided on it, being pressed down, with the cog and the self-blocking hook forming self-blocking fixation. A pressure channel is located in the ejection chamber along the pressure way of the second pressure projection. The protective rod is provided with a safety nozzle, and when the protective rod is installed, the safety nozzle covers the needle tip and occupie