An anesthesia device has a device (4, 5) for the supply of at least one first anesthetic and a second anesthetic in a quantitatively settable, controlled manner. A data processing unit (6) with a corresponding display (8) is set up for determining the current concentrations in the plasma or at the site of action from continuously supplied data on the quantities of the anesthetics administered with a module (10) for a pharmacokinetic compartment model calculation and for storing these concentration values. Concentration data is predicted for at least one point in time in the future and this is also calculated. An action module (20) keeps ready the curve of at least one anesthesia action parameter as a function of the concentrations of the anesthetics in a stored manner. A display module (30) displays on the display (8) at least one action diagram, in which the concentration of the first or second anesthetic as well as the sequence of the concentration data of the anesthesia curve obtained up to that point in time are displayed and the predicted concentration data are displayed with a separate symbol. In case of comparison with concentration set points, it is also possible to act automatically on the feed of the anesthetics in a controlled manner with the predicted concentrations.