To improve defective engagement between a sliding door and a frame body so as to simplify attachment of a sash roller and a magnetic catch by arranging the magnet catch on the front face of the sash roller in the sash roller installed with its front face exposed toward the sliding door traveling direction face.

In this sash roller 1, a magnet catch 30 is housed retractably from the front face 3 of the sash roller 1. A cut hole is bored in the position abutting to the magnet catch 30 in a vertical frame, and in the cut hole, a catch receiver made of a magnetic body is fixed flush with the vertical frame face. In this way, the magnet catch 30 is attracted by the catch receiver when a sliding door 40 provided with the sash roller 1 is closed, so that the sliding door 40 can be kept closed without any bounce. When the sliding door 40 is opened, the magnetized magnet catch 30 moves relatively to the travel of the sliding door 40 against a spring pressure from a coil spring 37 so as to be pulled out from the inside of the sash roller 1. In this way, the sliding door can be fit and maintained in the frame body, while an installation process can be also simplified.