Abstract: A tumbler lock comprises a rotatable cylinder member formed with a plurality of bottomed holes arranged in parallel along an axis of the rotatable member on a circle coaxial with the axis, a corresponding number of biasing springs disposed in the bottoms of the respective holes, a corresponding number of tumbler pins each formed with annular groove at a different axial position and inserted into different one of the holes against a biasing spring and a cylindrical stationary member for rotatably holding the rotatable member, wherein the rotatable cylinder member is formed with the corresponding number of radial holes each communicated with corresponding one of the bottomed holes and, wherein a corresponding number of recesses are formed on the inner surface of the stationary member at positions corresponding to the radial holes and wherein a corresponding number of balls are provided for each of the tumbler pins in the rotatable member in such a manner that, in a normal state, the rotation of the rotatable me