Mop convenient for the replacement of the consumptive material

A mop includes a molded mop casing having two mophead supporting faces connected together to show a double beveled configuration, a detached part pivotally connected to the molded mop casing between the mophead supporting faces, a mop shaft connected to the detached part and biasable with the mop shaft relative to the molded mop casing, a handle coupled to the mop shaft and movable forwards/backwards along the mop shaft, and an extending device mounted in the handle and the molded mop casing and movable by the handle between an extended position and a received position for locking/unlocking a consumptive material for enabling a user to mount/dismount the consumptive material conveniently without direct hand contact.