PURPOSE: To perform simply and quickly tense connection of two PC steel materials, by holding both ends of two PC steel materials fixed to a concrete structure by a jack, bringing the two close to each other, and connecting them by a coupler.

CONSTITUTION: When tensely connecting two PC steel materials 3, 3 having respective ends fixed to a concrete structure, a locking part 40 is formed in a screw 39 fixed to the end of the PC steel material and locked to the locking hole 21 of a reaction force frame 13 at the side of a jack 12. Further, a coupler 44 is loosely fitted around an inner nut 43 at the tip of the screw 39. A locking part 46 is formed in another PC steel material 3 and attached to the body 12 of the jack. An end of the PC steel material is brought close to another PC steel material by the action of the piston in the jack, and the ends of two PC steel materials 3, 3 are tensely connected. Then, the jack is removed, and tense connection of the two PC steel materials is made possible in tensing state.