The invention is directed to a temperature-controllable objective, particularly for microscopes and other optical equipment, which comprises a main barrel as the main component part of the objective. The main barrel contains at least one correction mount, cylinder sleeves, mounting rings, carrier rings and/or adjusting rings, and imaging optical elements. In order to control the temperature, at least one structural component part of the objective or an element arranged between structural component parts of the objective is constructed as a temperature-controllable element or as a temperature-controllable foil which is connected (not shown) by leads to a device for monitoring temperature. Further, a temperature gauge or temperature sensor is arranged in the objective and is likewise connected to the device for monitoring temperature.