A chuck mechanism of a charge-discharge test device for a thin secondary battery, comprising a supporting base including: a chuck unit comprising: a roller holding member formed to be movable in a direction toward a battery container body housing a thin secondary battery in front of the supporting base, and including on a front surface thereof a plurality of pairs of rollers rotatably disposed in parallel in a left-right direction; and a chuck holding member attached in front of the roller holding member, and including a plurality of chuck members each formed of a pair of strip-shaped metal plates (103, 105) which are inserted between the corresponding pair of rollers and whose tip end sides are spread open toward the front in a substantially V-shape in plan view; drive means for moving the chuck unit; and a restriction part (31l, 31m, 119) for restricting a forward movement of the chuck holding member, wherein the movement of the chuck holding member moved forward together with the roller holding member by the driving of the drive means is restricted by the restriction part (31l, 31m, 119), and the tip end sides of each of the chuck members of the chuck holding member inserted between the corresponding pair of rollers of the roller holding member are closed by the corresponding pair of rollers when the roller holding member moves forward even further, so that each of the chuck members chucks an electrode terminal (5, 7) of each of thin secondary batteries housed in the battery container body in correspondence with the chuck members. a chuck unit comprising: a roller holding member formed to be movable in a direction toward a battery container body housing a thin secondary battery in front of the supporting base, and including on a front surface thereof a plurality of pairs of rollers rotatably disposed in parallel in a left-right direction; and a chuck holding member attached in front of the roller holding member, and including a plurality of chuck members each formed of a pair of strip-shaped metal plates (103, 105) which are inserted between the corresponding pair of rollers and whose tip end sides are spread open toward the front in a substantially V-shape in plan view; a roller holding member formed to be movable in a direction toward a battery container body housing a thin secondary battery in front of the supporting base, and including on a front surface thereof a plurality of pairs of rollers rotatably disposed in parallel in a left-right direction; and a chuck holding member attached in front of the roller holding member, and including a plurality of chuck members each formed of a pair of strip-shaped metal plates (103, 105) which are inserted between the corresponding pair of rollers and whose tip end sides are spread open toward the front in a substantially V-shape in plan view; drive means for moving the chuck unit; and a restriction part (31l, 31m, 119) for restricting a forward movement of the chuck holding member, wherein the movement of the chuck holding member moved forward together with the roller holding member by the driving of the drive means is restricted by the restriction part (31l, 31m, 119), and the tip end sides of each of the chuck members of the chuck holding member inserted between the corresponding pair of rollers of the roller holding member are closed by the corresponding pair of rollers when the roller holding member moves forward even further, so that each of the chuck members chucks an electrode terminal (5, 7) of each of thin secondary batteries housed in the battery container body in correspondence with the chuck members.