A walking assisting device that transmits a force generated by a leg link to a user's trunk via a load transfer portion. The leg link includes a first link connected to the load transfer portion via a first joint portion, a second link connected to a foot attachment portion via a second joint portion, a third joint portion which connects the first link to the second link so as to be free to bend and stretch, and a driving source which drives the third joint portion. Even if a flexion angle of the third joint portion reaches zero degree, the controllability is maintained in the direction of pushing up the load transfer portion so that the leg link can be extended straight with the user's leg extended straight. An interlock system retracts and extends the second link and increases and decreases the flexion angle of the third joint portion.