PURPOSE: To provide a mechanism for clamping a carrier of surface mount ICs, in which types of carriers can be changed easily and quickly.

CONSTITUTION: Linear motion guides 21 are movable along the jaws 4 of an IC carrier 1, and at the tip of each guide is provided a pin 11 for opening and closing the jaws. The linear motion guides are provided with cam followers 22 engaged with a barrel cam 23, and they are moved with the rotation of the barrel cam on its axis. The barrel cam is driven through gears by a motor, which is controlled in such a manner that the barrel cam rotates in a range corresponding to the travel of the pins 11 depending on the type of IC carriers.