An electronic device includes a high-frequency transmission line member and a housing. The high-frequency transmission line member includes a flexible substrate, a signal conductor, and a ground conductor along the signal conductor. The housing is defined by a member separate from the high-frequency transmission line member and located at one principal surface side of the high-frequency transmission line member. The high-frequency transmission line member includes a first portion along the housing to face the housing, and a second portion spaced apart from the housing more than the first portion. The ground conductor is not provided at one principal surface side of the signal conductor in the first portion and is provided at least in the second portion.