PROBLEM TO BE SOLVED: To provide a folding method capable of stably folding a sheet-like article having a continuous part and an extension part.SOLUTION: A folding method relates to a method of folding a sheet-like article 1 having a continuous part and an extension part 1b using a folding device 100. The folding device 100 comprises a roller 120, suction holding means 130 provided on a side face facing outward in a cross direction of the roller, and a folding guide 140 provided downstream of the roller. The folding method includes: a fold forming step of feeding the article 1 to the folding guide 140 by the roller 120 while forming a fold along the conveying direction between a central region in a cross direction of the article and a side region S of the article along a conveying direction MD, which includes the extension part 1b; and a folding step of folding the side region S onto the central region by the folding guide 140 with the fold as a base point. During the fold forming step, the side region S is held in a state of pulling up the side region S by the suction holding means 130.SELECTED DRAWING: Figure 4【課題】連続部及び延出部を有するシート状の物品を安定して折り畳むことができる折り畳み方法を提供する。【解決手段】係る折り畳み方法は、連続部と延出部1bを有するシート状の物品1を折り装置100を用いて折り畳む方法に関する。折り装置100は、ローラ120と、ローラの交差方向の外側に向いた側面に設けられた吸引保持手段130と、ローラの下流に設けられた折りガイド140と、を備える。折り畳み方法は、ローラ120によって、物品の交差方向における中央領域と、延出部1bを含む搬送方向に沿った物品の側部領域Sとの間に、搬送方向MDに沿った折り目を形成しながら、物品1を折りガイド140へ送る折り目形成工程と、折りガイド140によって折り目を基点に側部領域Sを中央領域の上に折り畳む折り工程と、を有する。折り目形成工程中に、吸引保持手段130によって側部領域Sを引き上げた状態で側部領域Sを保持する。【選択図】図4