Sliding door device for vehicle

A sliding door apparatus for a vehicle, the sliding door apparatus comprising:

• a door configured to open or close a door opening portion formed in a vehicle body;
• a lower arm including a first end portion connected to an internal side of the door, and a second end portion configured to slide along a rail provided on the vehicle body;
• a lower arm carrier rotatably connected to the second end portion of the lower arm and configured to slide the lower arm while moving along the rail provided on the vehicle body;
• a lower arm rotor rotatably provided on the lower arm carrier and including an end portion connected to the lower arm so that the lower arm rotates;
• a catch configured to fix the door by engaging with the lower arm rotor after the door slides;
• and
• a pawl with which the catch engages by rotating so that a rotation of the catch is prevented,
• wherein the catch is rotatably provided at an upper end portion of a rail box that surrounds a second lower rail.