To provide float section repair method and device for a building finish material being the optimum for repair in the case of unavailability of the same tile and in a place allowing no replacing of a wall painting tile or the like and finishing repair construction work securely in a short period of time.

In this repair method for pouring adhesive 14 into a plurality of float sections 6 of the finish material 3 stuck and applied on a surface of a skeleton 1 of a building from the outside for repair by adhesion, an upper part suction hole 7 and a lower part fill hole 8 are drilled in joint 4 positions in each of a plurality of float sections 6, and an injector 12 including the adhesive 14 is set to each of the lower part fill holes 8, and a suction pipe 11 connected with a vacuum pump 18 is set to each of the upper part suction holes 7. Then, the adhesive 14 in the injector 12 is poured into each of the lower part fill holes 8 in a plurality of float sections 6 under low pressure all at once or sequentially, the vacuum pump 18 is operated to suck air through each of the upper part suction holes 7 in a plurality of float sections 6 to make pressure in each float section 6 negative pressure so that the poured adhesive 14 spreads all over each float section 6.