To provide a power feeding plug lock device capable of locking a power feeding plug to an inlet with easy work.

For fixing a power feeding plug to the inlet, a power feeding plug lock device 23 is mounted on an operation part 20 of a lock arm 17. At this time, a pair of restricting members 31, 31 are pushed by the operation part 20 and moved in mutually separating directions, and when locking grooves 47, 48 are aligned to each other, a lock plate 42 is half-fitted to the locking grooves 47, 48 by an energizing member 43. When the restricting members 31, 31 are moved to enter locking holes 32, 32 of the operation part 20 by energizing members 33, 33 and the restricting members 31, 31 are separated from the lock plate 42, the lock plate 42 is full-fitted to the locking grooves 47, 48. At this time, the restricting members 31, 31 are supported at their back faces by the lock plate 42 and held in a locking condition.