A lithographic apparatus is disclosed. The apparatus includes the following components: an illumination system configured to condition a radiation beam, a support constructed to support a patterning device, a substrate support constructed to hold a substrate, and a projection system configured to project the patterned radiation beam onto a target portion of the substrate. The patterning device is capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam. At least one of the components that experiences a heat load in use is provided with an integrally mounted heating element arranged to maintain the component at a substantially constant temperature.