To suck, grip, and convey an object to be conveyed in a box shape such as corrugated fiberboard having different size stably without requiring complicate control.

A suction tool 21a and a grip tool 22a and a suction tool 21b and a grip tool 22b are attached to a first linear guide unit 14 and a second linear guide unit 15 which can move along a circular track of a circular guide rail 12 provided on an arm 2a of a robot and one set of suction grip traveling bodies 17a and 17b provided in the first linear guide unit. The suction grip traveling bodies 17a, 17b move inward or outward by driving a ball screw by a servo motor 20 for the center of the circular track and suction and grip four corners of an object to be conveyed for conveyance.