A feed mechanism includes: a feed tray accommodating a roll body, a first sheet-shaped medium being rolled in a roll shape as the roll body, the feed tray including: a first accommodation portion accommodating the roll body; a pair of side walls respectively provided on both sides of the first accommodation portion in an axial direction of the roll body that is accommodated in the first accommodation portion; and a side guide disposed inside the pair of side walls.

Proposed is a method for automatically replacing an electrode reel of a secondary battery which includes a reel holder mounting step, an adhesive providing step, a production reel outer diameter detection step, a production reel moving step, a standby reel supply step, and a material connection step of connecting an electrode material of the production reel of the bobbin buffer part and an electrode material of the standby reel to each other by using the adhesive, and cutting a remaining electrode material of the production reel.