An apparatus for the thermal treatment of samples within sample containers comprises: a sample block a receiving region for the sample containers; a first temperature-control device thermally coupled to the sample block designed to set a temperature of the sample block; a cover plate arranged in the receiving region of the sample block; a second temperature-control device thermally coupled to the cover plate and designed to set a temperature of the cover plate; and a control unit connected to the first and the second temperature-control devices and designed to control the first and the second temperature-control device as to control the temperature of the sample block and the temperature of the cover plate such that the temperatures are coordinated with one another. A method for the thermal treatment of samples contained in sample containers is also disclosed.