PURPOSE: To make clamping of members for transporting various types of members with simple construction and operation and saved labor.

CONSTITUTION: A center shaft 29 and a cylindrical shaft 30 fitted closely onto it are supported rotatably by a case 24, the center shaft 29 and the cylindrical shaft 30 cooperate with each other so that they are reversely rotated synchronously with each other by the extension/contraction of a cylinder 34 installed on the case 24, and arm plates 55 and 56 are installed to the ends of the center shaft 29 and the cylindrical shaft 30, respectively. Thus both arm plates 55 and 56 are opened and closed by the reverse rotation of the center shaft 29 and the cylindrical shaft 30 to clamp a member.