To provide an insert fixing utensil by which an insert does not tilt or is not removed in the manufacturing process for a concrete product when the insert to be buried in the concrete product is fixed on the floor surface of a mold.

A component 2 (2) is inserted in a component 1 (1) which is attached to the floor surface of the mold. A nut (3) made of a chemical resin is attached to the male thread on the top section of the component 1 (1) which projects from the upper end of the central through-hole of the component 2 (2), and the nut (3) is tightened to fix the part 2 (2) to the part 1 (1).