A temporary storage apparatus for temporarily storing carriers between overhead travelling vehicles and a load port located in front of an equipment , the temporary storage apparatus comprising: a local vehicle provided with a hoist configured to raise and lower a carrier ; a travelling rail for the local vehicle passing over the load port and provided below a travelling path of the overhead travelling vehicles ; and a slidable buffer comprising: a cell configured to support a carrier thereon; and a guide mechanism configured to support and to slide the cell between an advanced position under the travelling rail and a backwards position laterally separated from the travelling rail , wherein the guide mechanism is configured to move between an active position laterally protruding from the travelling rail , and a retracted position laterally less protruding from the travelling rail by a shorter length than the active position and allowing an overhead travelling vehicle to transfer a carrier to the load port , wherein the travelling rail extends along a front face of the equipment to a waiting position for the local vehicle , and wherein the local vehicle is configured to wait at the waiting position when no work is allocated to the local vehicle , the temporary storage apparatus further comprising: a frame ; wherein the guide mechanism is attached to the frame in a rotatable manner about an axis parallel to the travelling rail together with the cell , and wherein the guide mechanism and the cell are separated from the advanced position and the backwards position under the travelling rail at the retracted position. a local vehicle provided with a hoist configured to raise and lower a carrier ; a travelling rail for the local vehicle passing over the load port and provided below a travelling path of the overhead travelling vehicles ; and a slidable buffer comprising: a cell configured to support a carrier thereon; and a guide mechanism configured to support and to slide the cell between an advanced position under the travelling rail and a backwards position laterally separated from the travelling rail , a cell configured to support a carrier thereon; and a guide mechanism configured to support and to slide the cell between an advanced position under the travelling rail and a backwards position laterally separated from the travelling rail , wherein the guide mechanism is configured to move between an active position laterally protruding from the travelling rail , and a retracted position laterally less protruding from the travelling rail by a shorter length than the active position and allowing an overhead travelling vehicle to transfer a carrier to the load port , wherein the travelling rail extends along a front face of the equipment to a waiting position for the local vehicle , and wherein the local vehicle is configured to wait at the waiting position when no work is allocated to the local vehicle , the temporary storage apparatus further comprising: a frame ; wherein the guide mechanism is attached to the frame in a rotatable manner about an axis parallel to the travelling rail together with the cell , and wherein the guide mechanism and the cell are separated from the advanced position and the backwards position under the travelling rail at the retracted position. a frame ; wherein the guide mechanism is attached to the frame in a rotatable manner about an axis parallel to the travelling rail together with the cell , and wherein the guide mechanism and the cell are separated from the advanced position and the backwards position under the travelling rail at the retracted position. <EOS>