In an antenna module, a main portion includes a plurality of insulating sheets made of a flexible material and laminated on each other. An antenna configured to transmit/receive a high-frequency signal is disposed in the main portion. A connection portion is disposed in the main portion and is connected to an electronic device that inputs/outputs the high-frequency signal. A signal transmission line is disposed in the main portion and has a strip line structure or a microstrip line structure to transmit the high-frequency signal. An impedance matching circuit is disposed in the main portion and between the antenna and end of a signal transmission line facing in a negative x direction. An impedance matching circuit is disposed in the main portion and between the connection portion and an end of the signal transmission line facing in a positive x direction.