A temporary storage apparatus for temporarily storing carriers between an overhead travelling vehicle travelling along a first travelling rail and a load port of an equipment , the temporary storage apparatus comprising: a local vehicle provided with a hoist configured to raise and lower a carrier and configured to travel; a second travelling rail for the local vehicle provided below the first travelling rail for the overhead travelling vehicle and extending to an area over the load port ; at least one slidable buffer configured to support a carrier thereon and to slide between a first position under the second travelling rail for the local vehicle and a second position laterally separated from the first position under the second travelling rail for the local vehicle ; and a controller configured to control the local vehicle and the slidable buffer , the apparatus being characterized in that the second travelling rail for the local vehicle is configured to extend from the area over the load port to a waiting position for the local vehicle shifted from the area over the load port , wherein the local vehicle is configured to wait at said waiting position, wherein the slidable buffer comprises a base and a movable pedestal configured to move forward from the base to a position under the second travelling rail for the local vehicle , wherein said base is fixed at a position laterally separated from the first position under the second travelling rail for the local vehicle , wherein a first sensor configured to detect that the pedestal is located at the first position under the second travelling rail for the local vehicle and a second sensor configured to detect that the pedestal is located at a position over the base are provided, and wherein said controller is configured and programmed to permit the overhead travelling vehicle and the local vehicle to transfer a carrier to the slidable buffer according to a detected position of the pedestal . a local vehicle provided with a hoist configured to raise and lower a carrier and configured to travel; a second travelling rail for the local vehicle provided below the first travelling rail for the overhead travelling vehicle and extending to an area over the load port ; at least one slidable buffer configured to support a carrier thereon and to slide between a first position under the second travelling rail for the local vehicle and a second position laterally separated from the first position under the second travelling rail for the local vehicle ; and a controller configured to control the local vehicle and the slidable buffer , the apparatus being characterized in that the second travelling rail for the local vehicle is configured to extend from the area over the load port to a waiting position for the local vehicle shifted from the area over the load port , wherein the local vehicle is configured to wait at said waiting position, wherein the slidable buffer comprises a base and a movable pedestal configured to move forward from the base to a position under the second travelling rail for the local vehicle , wherein said base is fixed at a position laterally separated from the first position under the second travelling rail for the local vehicle , wherein a first sensor configured to detect that the pedestal is located at the first position under the second travelling rail for the local vehicle and a second sensor configured to detect that the pedestal is located at a position over the base are provided, and wherein said controller is configured and programmed to permit the overhead travelling vehicle and the local vehicle to transfer a carrier to the slidable buffer according to a detected position of the pedestal . <EOS>