To provide a sliding door apparatus in a simple structure, which can prevent the occurrence of dangerous finger pinching, and which enables the door to be fully closed without the need for a cumbersome manual resetting operation.

This sliding door apparatus 30 includes frames 11 and 13 which are provided on a wall side constituting a doorway, and a sliding door 20 which is openably/closably installed in the frames 11 and 13. The sliding door apparatus 30 further includes a braking device 60 which comprises a braking block body 40 provided with a braking surface partially formed with a slope and attached to a head jamb 13 on a frame side, and a braking portion body 50 provided with a pressure contact roller coming into elastic pressure contact with the braking surface of the braking block body 40 and attached to the sliding door 20, and which brakes a closing motion directly before the full closing of the sliding door 20 by the force of making the pressure contact roller elastically repel the braking surface.