PURPOSE: To take out a parcel sent through home delivery service from a receiver box by using only one of two keys used for locking and prevent the key left in one of cylinder locks from being carried away due to a mischief, or the like, during a waiting time for a parcel.

CONSTITUTION: Two cylinder locks 21, 22 are provided on a base frame 1 fixed at the end of the opening side of the door 20 of a receive box 10. The first key 23 inserted in the first cylinder lock 21 is so designed that it can not be pulled out at any position other than the locking position. A sickle 3 is fixed in the inner cylinder of the first cylinder lock 21. A control lever 4 selectively engaged with the sickle 3 and a spring 42 for energizing the lever are provided. A cam piece 5 is installed in the inner cylinder of the second cylinder lock 22 in order to disengage the sickle 3 at the unlocking position from the control lever 4.