L-shaped grippers typically used for power assist suits have a problem in stably holding objects of arbitrary shape. To solve this problem, we developed a gripper with a ratchet mechanism consisting of linear motion and rotational motion parts. The gripper can be deformed according to the shape of the wearer’s hand and the shape of the object to be held, and the shape of the gripper can be fixed due to the rachet mechanism, thus objects of arbitrary shape can be held stably by this gripper and the burden of the wearers is reduced. We carried out experiments where four types of objects were held by the developed gripper. We showed that the developed gripper has reduced the wearer’s burden for two types of objects among four.