To provide a nail supply mechanism in a nailing machine capable of easily taking out a loaded linked nail 4 from a magazine 3 in the middle of nailing works.

The magazine 3 is provided with a linear nail guide surface 6 having a shoulder part 7 connecting to a nail port 5 and supporting the head of the linked nail 4 and a movable guide wall 9 opposed to the nail guide surface 6. A plurality of the linked nails 4 are loaded in parallel between the nail guide surface 6 and the movable guide wall 9 in mutually contacting states, the plurality of the linked nails 4 are pressed toward the guide surface 6 of the magazine 3 by a pressing means 16 provided in the movable guide wall 9 and the movable guide walls 9 are provided in a position disposed oppositely to the nail guide surface 6 of the magazine 3 and a position opening the nail guide surface 6 so as to be freely opened/closed.