To provide a spacer for construction capable of being simply fitted to a floor bar and beam bar assembled on a floor form and surely holding the level of the floor thickness and floor surface.

A reference level rod for surely holding the level of the floor thickness and the floor surface and a survey rod 3 are rotatably mounted in a suitable place of a fixture formed by a screw rod having L-shaped tip to be mounted on a reinforcement bar, a butterfly nut 2a screw-engaged with the screw rod and a washer 2b on the L-shaped screw rod through a spring to be integrated.