A processing target conveying device includes a conveying unit that takes out a processing target accommodated in a stocker. An adapter having a first engagement projection and a second engagement projection are attached to the processing target. The conveying unit includes: a first hook in which a first engagement recess configured to engage with the first engagement projection is formed； a second hook which is disposed to face the first hook in a front-rear direction and in which a second engagement recess configured to engage with a second engagement projection is formed； a first spring that applies elastic force so that the first hook moves toward the second hook when the first engagement projection is positioned in the first engagement recess； and a second spring that applies elastic force so that the second hook moves toward the first hook when the second engagement projection is positioned in the second engagement recess.
