A sealing/pump-up device for tire that not only ensures the storability of sealing agent but also realizes rapid supply of sealing agent into a pneumatic tire. By insertion of insert part (60A) of jig (60) in jig insertion aperture (42) of sealing device (10), aluminum seal (30) is burst through by means of boring member (50) to thereby drive the same in the container. As the distal end of the insert part (60A) locates in the vicinity of upper wall surface within liquid agent container (18), a compressor unit is operated to thereby supply compressed air into the liquid agent container (18). As the end portion of first passage (62) provided in the jig (60) lies in a position superior to the liquid surface of sealing agent (32), the compressed air realizes rapid supply of the sealing agent (32) into a pneumatic tire without surfacing in the form of bubbles through the sealing agent (32).