I will provide a modular prosthesis that mimics the subtalar joint of the foot of the [human] challenge. Providing a prosthesis which can be easily changed to the length of the foot or shoe size different by facilitating the variation. SOLUTION: A ankle component, and a forefoot component and has a circular portion with the at least one flat side and the curved top surface, circular shaped portion is joined to a rear portion of the forefoot component Modular prosthesis, wherein the forefoot component is a forefoot cushioning buffer portion which is located around the circular portion, that has a heel component. [Selection Figure Figure 2【課題】人間の足の距骨下関節を模倣したモジュール式義足を提供する。バリエーションを容易にして異なる靴のサイズまたは足の長さに容易に変更できる義足を提供する。【解決手段】くるぶし構成部材と、前足構成部材であって、曲面状頂面と少なくとも1つの平坦な側面とを備えた円形部を有し、該円形部は前記前足構成部材の後部に接合されている前足構成部材と、前記円形部の周囲に位置している前足クッション緩衝部と、かかと構成部材とを有することを特徴とするモジュール式義足。【選択図】図2