A device for producing a packaged electrode having an electrode sandwiched between a pair of separators includes: a conveyance unit configured to sequentially overlay the electrode and the pair of separators from a front end side in a conveying direction while conveying the electrode and the pair of separators; a joining unit configured to join lateral edges of the pair of separators together, the lateral edges being positioned in a direction intersecting the conveying direction; and a controller configured to control operations of the conveyance unit and the joining unit. The controller is configured to repeatedly perform joining a plurality of times from the front end side in the conveying direction, each of the joining being performed while moving the joining unit so that a speed of the joining unit relative to a conveyance speed of a workpiece approaches zero.