Abstract: The present invention, in deboning process for a pig thigh in which a pig thigh held by gripping on a transport line is sequentially deboned starting from a hind shank, comprises preliminary processing steps of: gripping the ankle side section of a work by transport/processing means; removing a hip bone, and a sacrum and a caudal vertebrae of the gripped work; and cutting-in for a hind shank and a femur, and the process further comprises the steps of: stripping a meat section around the hind shank after it is processed in the preliminary processing steps; exposing a fibula to detecting the base position of a fibula head as a first sensing step; stripping a meat section around above a joint and cutting an organic tissue exposed by the stripping for separation of leg section muscles; cutting a patelliform bone related section; stripping for the femoral region and detecting the base position of a femur head as a second sensing step; cutting a femur head related section; and separating by cutting the meat section