A differential gear has a simple structure, is able to produce a difference of differential limiting force between a driving operation of a vehicle in which the differential gear is installed and a coasting operation of the vehicle, secures the strength of a thrust bearing adopted for the differential gear, and provides a stabilized differential limiting force, in the driving operation, helical side gears receive thrusting forces acting away from each other, the differential case has inward support faces to axially support the helical side gears, the helical side gear has an annular inward counter face and an annular outward counter face on the inner circumferential side of opposite ends of a teeth area, and between the inward counter faces, there is a thrust bearing having a plurality of circumferentially arranged rollers.