In the walking assist device, defining rigidity of a portion from the user to a first joint as K1 [N/m], rigidity of a portion from the first joint to the second joint as K2 [N/m] and rigidity of a portion from the second joint to one of the feet of a free leg of the user as K31 [N/m], when the user is supported by the support member, they are set as: (K1 +K31)<；K2. With this, the assist force can avoid being affected by, in the direction of gravity, vertical displacement of a portion other than the main body of the device and the control accuracy of the assist force is enhanced accordingly, thereby improving the assisting feel sensed by the user P.
