A film member attaching device 1 comprising a table 100 on which a member to attach is placed, a film member supply mechanism 200, and a control device 300 that has a film member feed control function and an attachment control function, wherein the film member supply mechanism 200 has a release film advancing mechanism 220 that advances a release film 40 returned by a peeling unit 210, and the release film advancing mechanism 220 has an attaching-peeling synchronization mechanism 221 that peels off the release film 40 by actively synchronizing to the action of attaching a film member (polarization film) 30 when performing an action to attach the film member 30. Damage to the release film can be prevented by reducing the tension applied to the release film when attaching the film member to the member to attach while returning and peeling, with the peeling unit, the release film from the film member to which the release film is separably attached.