An insert-molded body and a molding method thereof are provided, which insert-molded body includes: a primary molded body having a first resin portion and a second resin portion; a terminal assembly consisting of one or a plurality of strip terminals; a bent portion formed on the terminal assembly and bent in a suitable angle; a first engaging portion and a second engaging portion protrusively provided on respective sides of the bent portion in a same direction; a first abutting face and a second abutting face provided on the first engaging portion and the second engaging portion, respectively; and a first end face and a second end face provided on the first resin portion and the second resin portion, respectively, wherein the first abutting face and the second abutting face abut against the first end face and the second end face, respectively, due to elastic restoring force arising on the terminal assembly by changing a bending angle of the bent portion. Thus, the structure of a metal mold to mold the primary molded body can be simplified, and trouble to assemble the terminal assembly to the primary molded body can be reduced.