To provide a motion estimation device and an operation assistance device which can be easily handled and can estimate a users intention of action early and with high accuracy.A motion estimation device includes a muscle motion detection unit that detects muscle motion based on a sensor signal of a non-contact type myoelectric potential sensor for detecting a myoelectric potential of a user, a motion estimation unit that corresponds to a joint of the users body And a motion state estimating unit that estimates an operation state of the user based on a sensor signal of a motion sensor that detects a state of the joint portion provided in the joint portion and a detection result of the muscle motion detection unit.(FIG.【課題】取り扱いが容易であり、ユーザの動作意思を早期にかつ精度よく推定可能な動作推定装置及び動作補助装置を提供する。【解決手段】動作推定装置は、ユーザの筋電位を検出するための非接触式の筋電位センサのセンサ信号に基づいて筋運動を検出する筋運動検出部と、ユーザの人体の関節に対応して設けられた関節部の状態を検出する運動センサのセンサ信号及び筋運動検出部の検出結果に基づいてユーザの動作状態を推定する動作状態推定部と、を備える。【選択図】図3
