A cylindrical battery cell includes a jelly-roll type electrode assembly having a structure in which a first electrode plate and a second electrode plate are wound in one direction with a separator being interposed therebetween, the first electrode plate including a first uncoated forming a plurality of winding turns; a battery can having an open portion in which the electrode assembly is accommodated and a partial closed portion provided at a side opposite thereto, the battery can being electrically connected to the second electrode plate; a current collector plate electrically connected to the first uncoated region of the first electrode plate; and a cell terminal connected to the current collector plate, the cell terminal including a terminal insertion inserted into the battery can through the through-hole. At least a part of a bottom surface of the terminal insertion portion being flat and electrically connected to the current collector plate.