A side seal plate transfer device, comprising: a pair of side seal plate preheating apparatuses for receiving and heating side seal plates which are used in connection with end surfaces of a pair of cooling rollers constituting a melting pool of a continuous casting apparatus; a pair of side seal plate pressing and attachment apparatuses disposed opposite to the two end surfaces of the cooling rollers respectively and capable of assembling and disassembling the side seal plates, and enabling the side seal plates to be pressed and attached to the end surfaces of the cooling rollers, characterized by a base having a quadrangular area configured to be utilized by an operator to perform operation and inspection on the melting pool, the side seal plate pressing and attachment apparatuses and the side seal plate preheating apparatuses, the melting pool, the cooling rollers, the side seal plate pressing and attachment apparatuses and the side seal plate preheating apparatuses being provided under the base; a pair of guide rails provided on the base, when viewed from above, at the outer side of the two end surfaces of the cooling rollers, extending linearly from the side seal plate pressing and attachment apparatuses to the side seal plate preheating apparatuses respectively; a pair of side seal plate transfer apparatuses, travelling on the respective guide rails, supporting the side seal plates in a detachable manner, and transferring the side seal plates between the side seal plate preheating apparatuses and the side seal plate pressing and attachment apparatuses; a first opening formed on the base above the melting pool; a pair of second openings, serving as paths for transferring the side seal plates from the side seal plate preheating apparatuses to the side seal plate transfer apparatuses, and formed on the base at a position where a preset distance is separated from the guide rails towards the cooling roller side; a pair of third openings, serving as paths for transferring the side seal plates from the side seal plate transfer apparatuses to the side seal plate pressing and attachment apparatuses, and formed on the base at a position where the preset distance is separated from the guide rails towards the cooling roller side. a pair of side seal plate preheating apparatuses for receiving and heating side seal plates which are used in connection with end surfaces of a pair of cooling rollers constituting a melting pool of a continuous casting apparatus; a pair of side seal plate pressing and attachment apparatuses disposed opposite to the two end surfaces of the cooling rollers respectively and capable of assembling and disassembling the side seal plates, and enabling the side seal plates to be pressed and attached to the end surfaces of the cooling rollers, characterized by a base having a quadrangular area configured to be utilized by an operator to perform operation and inspection on the melting pool, the side seal plate pressing and attachment apparatuses and the side seal plate preheating apparatuses, the melting pool, the cooling rollers, the side seal plate pressing and attachment apparatuses and the side seal plate preheating apparatuses being provided under the base; a pair of guide rails provided on the base, when viewed from above, at the outer side of the two end surfaces of the cooling rollers, extending linearly from the side seal plate pressing and attachment apparatuses to the side seal plate preheating apparatuses respectively; a pair of side seal plate transfer apparatuses, travelling on the respective guide rails, supporting the side seal plates in a detachable manner, and transferring the side seal plates between the side seal plate preheating apparatuses and the side seal plate pressing and attachment apparatuses; a first opening formed on the base above the melting pool; a pair of second openings, serving as paths for transferring the side seal plates from the side seal plate preheating apparatuses to the side seal plate transfer apparatuses, and formed on the base at a position where a preset distance is separated from the guide rails towards the cooling roller side; a pair of third openings, serving as paths for transferring the side seal plates from the side seal plate transfer apparatuses to the side seal plate pressing and attachment apparatuses, and formed on the base at a position where the preset distance is separated from the guide rails towards the cooling roller side.