A folding device to manufacture a stacked/folded type electrode assembly having unit cells (110, 111, 112, 113, 114, 120, 121, 122, 123, 124, 550) sequentially stacked in a state in which a separation film (200, 560) is disposed between the respective unit cells, the folding device comprising: a web supply unit to supply a web having plate-shaped unit cells arranged at a top of the separation film at predetermined intervals; a winding jig to rotate the unit cells while holding a first one of the unit cells of the web so that the unit cells are sequentially stacked in a state in which the separation film is disposed between the respective unit cells; and a rotary shaft compensation unit to compensate for a position of a rotary shaft of the winding jig in an advancing direction of the web, the advancing direction of the web being an X-axis direction, wherein the rotary shaft compensation unit periodically changes the position of the rotary shaft to compensate for the change in X-axis velocity of the web caused during winding of the plate-shaped unit cells, thereby uniformly maintaining tension of the web, wherein the compensation amount of the rotary shaft is configured to be changed at a period of a sine function, wherein the folding device is configured to be used with the unit cells being disposed on the separation film so that a first unit cell and a second unit cell are spaced apart from each other by a distance corresponding to at least one unit cell, and the distance between the unit cells after the second unit cell is gradually increased, characterised in that the winding jig is configured to fixedly hold the web at an upper end of one of the unit cells and a lower end of the separation film corresponding to the one of the unit cells, wherein the winding jig is constructed and arranged such as to have, in use, a rotational velocity of 20 to 200 rpm, wherein the rotary shaft compensation unit is configured to have an interconnected variable rotation structure (510, 520), the interconnected variable rotation structure including a rotary eccentric roller and a variable crank, wherein at a portion of the variable crank with which an eccentric shaft of the eccentric roller engages is formed a groove extending in the vertical direction by a rotational diameter of the eccentric shaft, wherein the variable crank is configured so that the movement of the variable crank in the vertical direction is restrained, and wherein the variable crank is operatively connected to a winding unit having the winding jig mounted thereto to compensate for a rotary shaft of the winding jig in the advancing direction of the web. a web supply unit to supply a web having plate-shaped unit cells arranged at a top of the separation film at predetermined intervals; a winding jig to rotate the unit cells while holding a first one of the unit cells of the web so that the unit cells are sequentially stacked in a state in which the separation film is disposed between the respective unit cells; and a rotary shaft compensation unit to compensate for a position of a rotary shaft of the winding jig in an advancing direction of the web, the advancing direction of the web being an X-axis direction, wherein the rotary shaft compensation unit periodically changes the position of the rotary shaft to compensate for the change in X-axis velocity of the web caused during winding of the plate-shaped unit cells, thereby uniformly maintaining tension of the web, wherein the compensation amount of the rotary shaft is configured to be changed at a period of a sine function, wherein the folding device is configured to be used with the unit cells being disposed on the separation film so that a first unit cell and a second unit cell are spaced apart from each other by a distance corresponding to at least one unit cell, and the distance between the unit cells after the second unit cell is gradually increased, characterised in that the winding jig is configured to fixedly hold the web at an upper end of one of the unit cells and a lower end of the separation film corresponding to the one of the unit cells, wherein the winding jig is constructed and arranged such as to have, in use, a rotational velocity of 20 to 200 rpm, wherein the rotary shaft compensation unit is configured to have an interconnected variable rotation structure (510, 520), the interconnected variable rotation structure including a rotary eccentric roller and a variable crank, wherein at a portion of the variable crank with which an eccentric shaft of the eccentric roller engages is formed a groove extending in the vertical direction by a rotational diameter of the eccentric shaft, wherein the variable crank is configured so that the movement of the variable crank in the vertical direction is restrained, and wherein the variable crank is operatively connected to a winding unit having the winding jig mounted thereto to compensate for a rotary shaft of the winding jig in the advancing direction of the web.