To provide a mechanical key which can downsize a key storage case, and which has good operability in use.

This mechanical key 4, which is housed in the key storage case 3, is equipped with a blade part 2 which is inserted into a cylinder lock 1 so that a turning operation for opening/closing the cylinder lock 1 can be performed. The mechanical key 4 has a knob part 5 which is connected to an upper end of the blade part 2 and which can be freely turned to a bent attitude from the attitude of being extended to be in line with the blade part 2. A fingerhold part 6 is protrusively provided on the side wall of the leading end of the knob part 5.