A SiC semiconductor device includes a main cell region and sense cell region being electrically isolated by an element isolation portion. The SiC semiconductor device includes a substrate, a first impurity region, a first current dispersion layer, first deep layers, a second current dispersion layer, a second deep layer, a base region, a trench gate structure, a second impurity region, first electrodes and a second electrode. The second impurity region, the first electrodes, and the second electrode are disposed at the main cell region and the sense cell region to form a vertical semiconductor element. The vertical semiconductor element allows a current flowing between the first electrode and the second electrode through a voltage applied to the gate electrode. The spacing interval between the deep layers at the element isolation portion is shorter than or equal to a spacing interval between the deep layers at the main cell region.