To easily replace a cylinder lock at a low cost when a user for furniture such as furnishings with a cylinder lock mechanism is changed.

In the cylinder lock mechanism in which a coil spring 5, tumbler pieces 3b for gages and tumbler pieces 3a for a stopper are fitted into a fitting groove 46 for the spring formed at multistages to the peripheral surface of a cylinder body 1 having a keyhole 2 at an outer end and an inserting hole, the cylinder body 1 is fitted to a cylinder case 12 and the cylinder body can be rotated in the cylinder case by operating a key 14 inserted from the keyhole, a gage section 17 engaged with a comparatively long-sized second key 16 inserted from the keyhole is mounted on the tumbler piece 3a for the stopper placed at the innermost end of the cylinder body 1, and the cylinder body 1 is extracted from the inside of the cylinder case 12 together with each tumbler piece 3 and the coil spring 5 by inserting the second key 16.