To certainly and inexpensively provide the combination of a cylinder lock and a key having a new outline irrespective of a well-known key outline, the cylinder lock being equipped with a rotatable lock disc and usable for both a lock operated in only one rotating direction of the key and a lock operable in both rotating directions.

At least one of lock disces 4 separately includes at least two faces 4a11, 4a12, which engage with a key 2 in a key opening 4a to rotate the lock disc 4 to an opened position of the lock, and at least one of the faces 4a11, 4a12 is sized and arranged so as to enable a combined face corresponding to the key 2 to select at least two combined values.