PRODUCING METHOD OF POWER STORAGE DEVICE

A producing method of a power storage device (200) includes roll pressing (S1) a mixture laminated portion (114) of a wide strip-shaped electrode plate (110), non-laminated-portion stretching (S2) of stretching a pair of mixture non-laminated portions (115) of the wide strip-shaped electrode plate (110) in a longitudinal direction (DA), laminated-portion stretching (S3) of stretching a pair of mixture non-laminated-portion-side sections (114b) of the mixture laminated portion (114) located on the mixture non-laminated portion (115) side, cutting (S4) the wide strip-shaped electrode plate (110) at a center (CL) of a width direction (DB) in the longitudinal direction (DA) to divide into two strip-shaped electrode plates (120), winding up (S5) the two strip-shaped electrode plates (120) around winding cores (81, 91) with applying tensile force in the longitudinal direction (DA) in a roll-like shape to form electrode rolls (180, 190), and storing (S6) each of the electrode rolls (180, 190).