This parallel link mechanism (1) is provided with proximal and distal link hub (2), and three or more link mechanisms. The link mechanisms are three-joint chain link mechanisms comprising four revolute pairs, and are configured from the proximal and distal terminal link members (5) and a center link member. A revolute pair of the link mechanisms comprises a pair of pair constituent members (2, 5) linked to one another via a bearing (12), and a shaft unit (13) provided on one (5) of the pair constituent members is fit in the inner circumference of the inner ring (12a) of the bearing, and an annular inner surface forming part (15) provided on the other (2) of the pair constituent members (2) is fit on the outer circumference of the outer ring (12b) of the bearing (12). By means of the shaft unit (13) and the annular inner surface forming part (15), a seal structure (19, 21) is constructed which limits the coming and going of lubricant between the internal and external part of the bearing (12).