A device for dispersing a sample of dry powder onto a surface in a dispersion chamber. The device includes a dispersion chamber situated in an environment, and a pressure source that provides a pressure difference between the environment and an inside of the dispersion chamber. The surface is positioned in the dispersion chamber. The sample of dry powder is introduced into the dispersion chamber through a membrane that is interposed between the environment and the inside of the dispersion chamber and on which the sample is disposed. The membrane is rupturable so as to open into the dispersion chamber when a predetermined pressure difference across the membrane is exceeded. This permits entry of a fluid in the environment through the ruptured membrane, and movement of the dry powder sample in an evenly dispersed manner without producing an ordered movement of powder grains in the dispersion chamber.