To provide an easy-to-manufacture parking lock device with a simple structure.

This parking lock device 20 comprises switch means 35 for switching between a lock condition for locking an output shaft 34 and a canceling condition for canceling the output shaft 34; and holding means 58 for holding the canceling condition. The switch means 35 has a cylinder 21, a piston 22 and a piston rod 23. The holding means 58 has an actuation element 40 actuating to restrain a movement of the piston 22 and allow the movement of the piston 22, and actuation means 50 opposed to the piston rod 23 and actuating the actuation element 40 together with the piston rod 23. The actuation element 40 has a bottom part 41 pressed by the piston rod 23 and the actuation means 50, and a plurality of arm parts 42 positioned outside a movement path of the piston rod 23 and locked to a lock part 31 of the piston rod 23.

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