A posture estimation device that is capable of highly precisely estimating the posture of an object comprising multiple parts. Said device (100) comprises: a posture information database (110) that for each of multiple postures, holds posture information that defines the placement of multiple parts; a fitting unit (160) that computes, for each of the parts in an image, a correlation level between the placement of the parts and the posture information; a difficulty level information table (130) that holds an estimation difficulty level that is a degree of difficulty of estimating each part position and computed on the basis of each parallel line components of each of the parts contained in the posture information; and a posture estimation unit (170) that to the correlation level, applies a weighting based on the estimation difficulty level, and on the basis of the weighted correlation level, estimates the posture of the object.