An inductor module includes a laminate where multiple insulator layers are laminated, a main line conductor in the shape of a straight line formed on the laminate, a current detection conductor that is formed on the laminate and magnetically coupled with the main line conductor, and coil conductors that are formed on the laminate and constitute an inductor element. An absolute value of a coupling coefficient between the main line conductor and inductor element, and an absolute value of a coupling coefficient between the current detection conductor and the inductor element, are each smaller than an absolute value of a coupling coefficient between the main line conductor and the current detection conductor. Thus, an inductor module that detects current and is used as an inductor element, and an electric power transmission system including the inductor module, are provided.