To provide a mounting body, along with a communication module and a communication device, capable of efficiently radiating the heat of a communication component in vertical direction and lateral direction, with a manufacturing cost being suppressed.

On the communication module B, a mounting 10 where a power device 11 is mounted on a mounting substrate 12 and a heat radiation plate 13, is arranged. The heat radiation plate 13 includes a main surface part 13a on which the mounting substrate 12 is placed, and an upright part 13b extending vertically from the end part of the main surface part 13. The heat of the power device 11 is radiated from a heat radiation path Ht in vertical direction and a heat radiation path Hh in lateral direction. The heat radiation path Ht in vertical direction runs from the power device 11 toward a body part 31 of a heatsink 30 through the main surface part 13a of the heat radiation plate 13. The heat radiation path Hh in lateral direction runs from the main surface part 13a of the heat radiation plate 13 to the upright part 13b, a cable terminal 12, and a cable line 20. Since heat radiation through the cable line 20, especially a ground conductor 23, is possible, a heat radiation path expands in lateral direction.