To provide an opening part device as a barrier-free door enabling even a wheelchair to gain access thereto.

This opening part device comprises a frame body having an upper frame, a lower frame 30, and right and left side frames and a lifted sliding screen stored in the frame body. A guide frame 220 having a guide groove 210 is fitted to a lower frame, and a guide member 300 having an engagement part engaged with the guide groove is fitted to the lower part of the lifted sliding screen. The engagement part is fitted into the guide groove through an opening 310 formed in either of longitudinal ends of the guide groove, the opening/closing operation of the lifted sliding screen is guided by the guide member in association with the guide groove, and a cap 280 is fitted to the opening, or a seal part 282 is fitted to the sliding screen.