A semiconductor element for current control comprising: on the same semiconductor substrate , a main MOSFET configured to drive a current; and a sense MOSFET that is connected in parallel to the main MOSFET and that is configured to perform current detection of the main MOSFET, wherein the main MOSFET is surrounded by a first trench groove , the sense MOSFET is surrounded by a second trench groove , wherein a thermal conductivity of the first trench groove surrounding the main MOSFET is larger than a thermal conductivity of the second trench groove surrounding the sense MOSFET, characterised in that: a thermal conduction coefficient (λ m /t m ) per unit length of the first trench groove surrounding the main MOSFET having the width t m and the thermal conductivity λ m of material in the first trench is larger than a thermal conduction coefficient (λ s/ t s ) per unit length of the second trench groove surrounding the sense MOSFET having a width t s and the thermal conductivity λ s of material in the second trench, in that a width of the second trench groove surrounding the sense MOSFET is larger than a width of the first trench groove surrounding the main MOSFET, and in that a thermal resistance of the first trench groove surrounding the main MOSFET and a thermal resistance of the second trench groove surrounding the sense MOSFET are inversely proportional to the area of the element region surrounded by the first and second trench grooves , the thermal resistance of the first trench groove being determined by dividing the reciprocal of the thermal conduction coefficient of the first trench groove by the cross-sectional area around the main MOSFET of the first trench groove, and the thermal resistance of the second trench groove being determined by dividing the reciprocal of the thermal conduction coefficient of the second trench groove by the cross-sectional area around the sense MOSFET of the second trench groove. the main MOSFET is surrounded by a first trench groove , the sense MOSFET is surrounded by a second trench groove , wherein a thermal conductivity of the first trench groove surrounding the main MOSFET is larger than a thermal conductivity of the second trench groove surrounding the sense MOSFET, a thermal conduction coefficient (λ m /t m ) per unit length of the first trench groove surrounding the main MOSFET having the width t m and the thermal conductivity λ m of material in the first trench is larger than a thermal conduction coefficient (λ s/ t s ) per unit length of the second trench groove surrounding the sense MOSFET having a width t s and the thermal conductivity λ s of material in the second trench, in that a width of the second trench groove surrounding the sense MOSFET is larger than a width of the first trench groove surrounding the main MOSFET, and in that a thermal resistance of the first trench groove surrounding the main MOSFET and a thermal resistance of the second trench groove surrounding the sense MOSFET are inversely proportional to the area of the element region surrounded by the first and second trench grooves , the thermal resistance of the first trench groove being determined by dividing the reciprocal of the thermal conduction coefficient of the first trench groove by the cross-sectional area around the main MOSFET of the first trench groove, and the thermal resistance of the second trench groove being determined by dividing the reciprocal of the thermal conduction coefficient of the second trench groove by the cross-sectional area around the sense MOSFET of the second trench groove. <EOS>