A measuring device for determining a temperature-compensated dielectric value of a medium, comprising: - A measuring probe, with: ∘ an electrically conductive inner conductor, which is rod-shaped along an axis (a) at least in a partial area, ∘ an outer conductor which is arranged around the inner conductor and has at least one electrically conductive inner wall, the inner wall being formed symmetrically about the axis (a) in such a way that the inner wall widens along the axis (a), ∘ a temperature sensor, ▪ which is arranged in a first end region of the inner conductor, towards which the inner wall of the outer conductor expands, ▪ which has at least two electrical connections (1131, 1132), the first connection being at the potential of the inner conductor, wherein the measuring probe is designed such that the first end region of the inner conductor, in which the temperature sensor is arranged, is aligned towards the medium when the measuring device is installed, - a control/evaluation unit, which is designed, ∘ to determine the temperature of the medium via the second connection of the temperature sensor, ∘ to couple a high-frequency electrical signal (s HF) into the inner conductor or the outer conductor and to receive a corresponding received signal (r HF), and ∘ in order to determine the dielectric value of the medium in a temperature-compensated manner using the determined temperature and the received signal (r). HF - A measuring probe, with: ∘ an electrically conductive inner conductor, which is rod-shaped along an axis (a) at least in a partial area, ∘ an outer conductor which is arranged around the inner conductor and has at least one electrically conductive inner wall, the inner wall being formed symmetrically about the axis (a) in such a way that the inner wall widens along the axis (a), ∘ a temperature sensor, ▪ which is arranged in a first end region of the inner conductor, towards which the inner wall of the outer conductor expands, ▪ which has at least two electrical connections (1131, 1132), the first connection being at the potential of the inner conductor, wherein the measuring probe is designed such that the first end region of the inner conductor, in which the temperature sensor is arranged, is aligned towards the medium when the measuring device is installed, ∘ an electrically conductive inner conductor, which is rod-shaped along an axis (a) at least in a partial area, ∘ an outer conductor which is arranged around the inner conductor and has at least one electrically conductive inner wall, the inner wall being formed symmetrically about the axis (a) in such a way that the inner wall widens along the axis (a), ∘ a temperature sensor, ▪ which is arranged in a first end region of the inner conductor, towards which the inner wall of the outer conductor expands, ▪ which has at least two electrical connections (1131, 1132), the first connection being at the potential of the inner conductor, ▪ which is arranged in a first end region of the inner conductor, towards which the inner wall of the outer conductor expands, ▪ which has at least two electrical connections (1131, 1132), the first connection being at the potential of the inner conductor, - a control/evaluation unit, which is designed, ∘ to determine the temperature of the medium via the second connection of the temperature sensor, ∘ to couple a high-frequency electrical signal (s HF) into the inner conductor or the outer conductor and to receive a corresponding received signal (r HF), and ∘ in order to determine the dielectric value of the medium in a temperature-compensated manner using the determined temperature and the received signal (r). HF ∘ to determine the temperature of the medium via the second connection of the temperature sensor, ∘ to couple a high-frequency electrical signal (s HF) into the inner conductor or the outer conductor and to receive a corresponding received signal (r HF), and ∘ in order to determine the dielectric value of the medium in a temperature-compensated manner using the determined temperature and the received signal (r). HF