A steel plate splicing facility includes, a steel plate heating apparatus for retrieving and heating a preceding steel plate and a following steel plate, and a shear-joining apparatus for clamping a tail end portion of the preceding steel plate and a leading end portion of the following steel plate in an overlapping condition by a die and a clamp and shearing them with a punch, such that surfaces of the tail end portion and the leading end portion are newly formed and brought in contact with each other in order to them. The shear-joining apparatus joins the preceding and following steel plates at a temperature equal to or higher than 350° C. and at a percentage clearance c/t equal to or lower than 5%, c/t being defined by c/t=D/(t1+t2)×100 where D represents a distance between the punch and the die, and t1 and t2 represent a thickness of respective steel plates.