The invention relates to a temperature probe for an oven, comprising in one embodiment a longitudinal housing in the form of a spit. A temperature sensor and an electronic unit are arranged in a tip and are connected at the other end to emitting means. The temperature probe comprises a thermogenerator for producing energy. The thermogenerator uses a temperature difference between a higher temperature inside the oven and a lower core temperature in a food product, such as roast, in which the temperature probe is inserted, for producing energy for operating the emitting means.