Provided is a semiconductor device capable of reducing a temperature-dependent variation of a current sense ratio and accurately detecting current. In the semiconductor device, at least one of an impurity concentration and a thickness of each semiconductor layer is adjusted such that a value calculated by a following equation is less than a predetermined value: [ ∑ i = 1 n ⁢ ( R Mi × k Mi ) - ∑ i = 1 n ⁢ ( R Si × k Si ) ] / ∑ i = 1 n ⁢ ( R Mi × k Mi ) where a temperature-dependent resistance changing rate of an i-th semiconductor layer (i=1 to n) of the main element domain is RMi; a resistance ratio of the i-th semiconductor layer of the main element domain relative to the entire main element domain is kMi; a temperature-dependent resistance changing rate of the i-th semiconductor layer of the sense element domain is RSi; and a resistance ratio of the i-th semiconductor layer of the sense element domain to the entire sense element domain is kSi.