To make the outward appearance of a fixing member for fixing a jamb of a sliding door satisfactory by concealing the fixing member without giving a sense of heterogeneity and a sense of incongruity.

In a jamb 13 fixed to a substrate material 15 by machine screws 16, a door stop 30 is fixed to a position corresponding to a machine screw driving position so as to extend in a longitudinal direction of the jamb, thereby concealing machine screw heads. Even if there is a clearance between a door end and a jamb surface when a sliding door is closed, light leaked from the clearance is blocked by the door stop. Thus, leakage of light to a room on the door stop installation side is prevented. The door stop used for a door frame is used also for a sliding door frame, thereby facilitating member management and giving a sense of integrity into a dwelling.