When a packed column having a pressure-absorbing mechanism satisfies the following conditions, the pressure absorbing mechanism has a sufficient packings-supporting ability in spite of its simplicity, the disorder of flow of fluid is slight and the effect of separation of materials is high: (1) the inside diameter (D cm) is 10 cm or more, (2) the aforesaid pressure-absorbing mechanism cmprises solid parts and passage spaces through which packings can pass, (3) the specified circumference ratios of most of said passage spaces are 10/D or more and their lengths in the flow direction are larger than the -1.5th power of the circumference ratio, (4) the above passage spaces exist within 1 cm from any position on the upper and lower sides of the aforesaid solid parts, and (5) the specified shielding degree of the pressure-absorbing mechanism is 0.01 or more and 0.8 or less.