The manufacturing process for ITER toroidal field (TF) coils must be demonstrated as effective in order to meet the criteria for qualification. Since impregnation of the insulation system is one criterion for qualification in this study, we performed impregnation tests using a cyanate-ester/epoxy blended resin, chosen for its excellent resistance to radiation. To establish the insulation and impregnation procedure in the TF coil manufacturing process, three types of trials were performed: 1) impregnation tests using an acrylic model to fix the impregnation conditions; 2) an impregnation test using a metallic model to confirm that no void remains in the insulation layer after curing in the D-shaped configuration; and 3) insulation and impregnation trials using a 1/3-scale double-pancake (DP) model. The results of these trials were used to determine the insulation and impregnation procedures for manufacturing ITER TF coils.