Abstract: Provided is a thermal cycler including a housing, the housing with a thermal block having sample wells, each for receiving a test sample in a sample vessel, an electric heater for heating the thermal block, a power supply and an electronic control for controlling the electric heater, and a temperature analysis and/or verification unit for analyzing and/or verifying a thermal performance of the thermal block. Also provided is a method for analyzing or verifying a thermal performance of a thermal cycler and for calibrating the thermal cycler. The thermal cycler has a temperature analysis and/or verification unit integrated into the housing and connected to the power supply and electronic control by an internal interface, whereas the method is characterized by the following steps: providing the thermal cycler with an integrated temperature analysis and/or verification unit and using the integrated temperature analysis and/or verification unit for self-calibration of the thermal cycler.