Abstract: A knob comprises a knob cap and a moving block. The knob and the moving block are connected by inserting the moving block into the knob cap and by engaging nails formed on an inner surface of an enlarged diameter portion as an opening end of the knob cap to engagement holes formed in a fitting portion of the moving block. A bottom wall of the knob cap has an inner surface provided with projections at three equally divided positions on the circumference around the axis center, the projection having a front end provided with an inclined surface. The moving block is automatically aligned with the knob cap by making a corner of the inner peripheral edge in a ring-shaped front wall be in contact with the inclined surface. There can be obtained the knob in which the moving block can be freely cut in thickness, and the knob cap and the moving block can be aligned with each other without use of an adhesive agent accompanied by any dirt or operation jobs and unified without an axial gap.