A walking assist device characterized by comprising: a frame; a plurality of wheels provided on the frame and including at least one driving wheel; at least one traveling drive unit configured to drive the at least one driving wheel; a battery configured to operate the at least one traveling drive unit; a pair of right and left handles (20R, 20L) configured to be gripped by a user and being moveable in a frame front-rear direction that is a front-rear direction of the frame; handle condition detection units (21RS, 21LS) configured to detect conditions of the respective handles (20R, 20L); an electronic control unit configured to control the at least one traveling drive unit based on the conditions of the handles (20R, 20L) that are detected based on detection signals from the respective handle condition detection units (21RS, 21LS); a pair of right and left shafts (21R, 21L) fixed to the respective handles (20R, 20L) and extending in the frame front-rear direction; and a pair of right and left tubes (30R, 30L) that are attached to the frame so as to extend in the frame front-rear direction, the tubes (30R, 30L) being configured to house the respective shafts (21R, 21L) such that the shafts (21R, 21L) are movable in the frame front-rear direction, wherein a reference shaft position is set for each of the shafts (21R, 21L), the reference shaft position being a reference position in the frame front-rear direction relative to the tube (30R, 30L) that houses the shaft (21R, 21L); and each of the tubes (30R, 30L) is provided with a shaft position recovery portion configured to return, to the reference shaft position, the shaft (21R, 21L) and the handle (20R, 20L) moved forward or rearward from the reference shaft position, and each of the tubes (30R, 30L) is provided with a locking mechanism switchable between a locked state in which the shaft (21R, 21L) is held within a fore-and-aft limit range in the frame front-rear direction such that the shaft (21R, 21L) is located in vicinity of the reference shaft position, and an unlocked state in which the shaft (21R, 21L) is permitted to move in the frame front-rear direction beyond the fore-and-aft limit range in the frame front-rear direction. a frame; a plurality of wheels provided on the frame and including at least one driving wheel; at least one traveling drive unit configured to drive the at least one driving wheel; a battery configured to operate the at least one traveling drive unit; a pair of right and left handles (20R, 20L) configured to be gripped by a user and being moveable in a frame front-rear direction that is a front-rear direction of the frame; handle condition detection units (21RS, 21LS) configured to detect conditions of the respective handles (20R, 20L); an electronic control unit configured to control the at least one traveling drive unit based on the conditions of the handles (20R, 20L) that are detected based on detection signals from the respective handle condition detection units (21RS, 21LS); a pair of right and left shafts (21R, 21L) fixed to the respective handles (20R, 20L) and extending in the frame front-rear direction; and a pair of right and left tubes (30R, 30L) that are attached to the frame so as to extend in the frame front-rear direction, the tubes (30R, 30L) being configured to house the respective shafts (21R, 21L) such that the shafts (21R, 21L) are movable in the frame front-rear direction, wherein a reference shaft position is set for each of the shafts (21R, 21L), the reference shaft position being a reference position in the frame front-rear direction relative to the tube (30R, 30L) that houses the shaft (21R, 21L); and each of the tubes (30R, 30L) is provided with a shaft position recovery portion configured to return, to the reference shaft position, the shaft (21R, 21L) and the handle (20R, 20L) moved forward or rearward from the reference shaft position, and each of the tubes (30R, 30L) is provided with a locking mechanism switchable between a locked state in which the shaft (21R, 21L) is held within a fore-and-aft limit range in the frame front-rear direction such that the shaft (21R, 21L) is located in vicinity of the reference shaft position, and an unlocked state in which the shaft (21R, 21L) is permitted to move in the frame front-rear direction beyond the fore-and-aft limit range in the frame front-rear direction. a locked state in which the shaft (21R, 21L) is held within a fore-and-aft limit range in the frame front-rear direction such that the shaft (21R, 21L) is located in vicinity of the reference shaft position, and an unlocked state in which the shaft (21R, 21L) is permitted to move in the frame front-rear direction beyond the fore-and-aft limit range in the frame front-rear direction.