Assembly equipment comprising: a base ; a first robot arm set on the base ; a second robot arm set on the base ; a first holding hand connected to the first robot arm at an distal end of the first robot arm ; a second holding hand connected to the second robot arm at an distal end of the second robot arm ; and a control device configured to control the first and second robot arms (2 and 3) and the first and second holding hands (4 and 5), wherein the first holding hand comprises an attachment connected to the first robot arm at the distal end of the first robot arm , and an aligning holding mechanism , the attachment being rotatable around a first axis of rotation (a), and wherein a cooperative working area of the first and second holding hands (4 and 5) is provided in an overlapping area where working areas of the first and second holding hands (4 and 5) overlap with each other, wherein the first robot arm and the second robot arm are set on the base at different positions from each other to oppose each other on the base , the attachment further comprises a rotation mechanism which is rotatable around a second axis of rotation (b) located to intersect the first axis of rotation (a), the rotation mechanism is equipped with said aligning holding mechanism which is rotated by said rotation mechanism around the second axis of rotation (b), the rotation mechanism is attached to the first robot arm with the attachment being disposed therebetween in a state in which the second axis of rotation (b) and the first axis of rotation (a) intersect with each other, and the first holding hand is connected to be turnable about a turn shaft (c) at the distal end of the first robot arm , the turn shaft (c) intersecting the first axis of rotation (a) and being positionable perpendicularly to both the second axis of rotation (b) and the first axis of rotation (a). a base ; a first robot arm set on the base ; a second robot arm set on the base ; a first holding hand connected to the first robot arm at an distal end of the first robot arm ; a second holding hand connected to the second robot arm at an distal end of the second robot arm ; and a control device configured to control the first and second robot arms (2 and 3) and the first and second holding hands (4 and 5), wherein the first holding hand comprises an attachment connected to the first robot arm at the distal end of the first robot arm , and an aligning holding mechanism , the attachment being rotatable around a first axis of rotation (a), and wherein a cooperative working area of the first and second holding hands (4 and 5) is provided in an overlapping area where working areas of the first and second holding hands (4 and 5) overlap with each other, wherein the first robot arm and the second robot arm are set on the base at different positions from each other to oppose each other on the base , the attachment further comprises a rotation mechanism which is rotatable around a second axis of rotation (b) located to intersect the first axis of rotation (a), the rotation mechanism is equipped with said aligning holding mechanism which is rotated by said rotation mechanism around the second axis of rotation (b), the rotation mechanism is attached to the first robot arm with the attachment being disposed therebetween in a state in which the second axis of rotation (b) and the first axis of rotation (a) intersect with each other, and the first holding hand is connected to be turnable about a turn shaft (c) at the distal end of the first robot arm , the turn shaft (c) intersecting the first axis of rotation (a) and being positionable perpendicularly to both the second axis of rotation (b) and the first axis of rotation (a). <EOS>