To provide an insertion implement 3 which not only enables a separator 9 to be fixed to a form panel 2 but also enables interior and exterior finishing materials 6 etc. to be firmly and easily fixed to a concrete wall etc., and a concrete form 1 using the insertion implement 3.

In the form panel 2, a plurality of approximately U-shaped cross-section rib portions 2a opened on one side surface are formed in parallel by bending a thin metal plate; and an opening 5 for inserting the separator 9 or the insertion implement 3 is provided in the rib portion 2a, and formed in a contour shape comprising a large opening 5a and a narrow small opening 5b continuing below the large opening 5a. After the insertion implement 3 is inserted through the large opening 5a up to a position in which the groove portion 3a is formed, the insertion implement is moved downward to a small opening 5b from the large opening 5a; and the groove portion 3a and an edge portion of the small opening 5b are fitted together and fixed to the form panel 2.