A steer-by-wire steering device includes a first member, a second member, and a stopper. The first member includes a first base surrounding an input shaft and rotatable, a first protrusion protruding from the first base in a radial direction or in an axial direction, and a first weight provided on the first base so as to make a weighted center consistent with a center of the input shaft. The second member is rotatable together with the first member with the first protrusion being abutting the second protrusion. The stopper is provided on a trajectory of the second protrusion, and is capable of restricting the turn of a steering wheel via the input shaft when abutting with the second protrusion.