To provide a clamp cylinder capable of executing the temperature control for a stamping die and simultaneously easily fitting the stamping die to the clamp cylinder and adjusting the same.

This clamping cylinder is provided for receiving and fixing a cylindrical stamping die having a structured surface for manufacturing hologram or the like. In the clamp cylinder having an outer cylinder casing closed by a front cover and fitted to a shaft, the cylinder casing 1 is provided with plural holes 23 connected to a compressed air line 22 conducted through the interior of the cylinder casing 1, the plural holes are connected to a compressed air source, and the inside of the cylinder casing 1 is provided with a cavity for a temperature control medium circulating through an inlet and an outlet (cavities 6, 6a, 8).