To provide a gas cooler having improved cooling efficiency by increasing a heat transfer area, while reducing the deposition of scales on the outer peripheral face of a gas distribution pipe by using fins for disturbing the flow of a cooling medium.

The gas cooler 1 comprises the gas distribution pipe 2 arranged in an outer cylinder 3 for distributing high temperature gas, and the cooling medium to be distributed in a space between the gas distribution pipe 2 and the outer cylinder 3 for cooling the high temperature gas. The gas distribution pipe 2 has a number of fins 2a arranged on the outer peripheral face.