To prevent the occurrence of a breakage accident and obtain an excellently durable handle unit by setting the thickness of a clamping plate in which an operational projection provided on a handle contacts to the inner wall surface for locking and unlocking operation to be adequate for concealing substantially the overall length of the operational projection.

In the case 1, a handle 2 is pivoted by a first pivot 3, and a clamping plate 4 is pivoted by a second pivot 5. The case 1 is secured to a door 25, and the operational projection 6 of the handle is jointed to the receiving hole 7 of the clamping plate 4. The thickness of the clamping plate 4 is set to be adequate for concealing substantially the overall length of the operational projection 6. When the handle is projection turned, the lateral surface part of the operational projection 6 contacts to the inner wall surface of the receiving hole 7 of the clamping plate 4 so a to turn about the second pivot 5 and release a chain lock. When the handle 2 is pushed into the case 2, the other inner wall surface of the receiving hole is pushed by the operational projection 6 so as to reversely turn about the second pivot and perform locking. This allows the inner wall surface and operational projection to be in surface contact with each other, resulting in enhanced durability.