A magnetic core member, an antenna module, and a portable communication terminal having this, which have a configuration capable of satisfying enhancement of communication characteristics of antenna coils as well as their sufficient electromagnetic shielding function from a shield plate. A magnetic core member (4) is disposed between an antenna substrate having antenna coils (11), (12) formed therein and a conductive shield plate (3), and is formed by filling an insulating material (30) with a magnetic powder (31). The magnetic core member (4) has a two-layered structure including a first layer (4A) and a second layer (4B), thereby making a filling rate of the magnetic powder (31) in the first layer (4A) be lower than that of the magnetic powder (31) in the second layer (4B) so that a first surface (4a) on a side opposed to the antenna substrate (2) and a second surface (4b) on a side opposed to the shield plate (3) have magnetic properties different from each other.