To provide a mobile electronic device capable of improving workability.

A mobile phone 1 has: a conductive hinge holder 29 which connects a display housing 5 with an operation housing 3 to be relatively moved; and a circuit board 27 arranged in the display housing 5. The display case 5 has a display front case 15 and a display rear case 17 fixed opposite to each other. The circuit board 27 has a ground layer 27g provided on one principal plane (mounting plane 27a), and is stacked by turning the other principal plane (rear plane of the mounting plane 27a) to the inner side plane of the display front case 15 opposite to the display rear case 17. The hinge holder 29 has: a base 53 arranged in parallel with the circuit board 27 on the inner side plane of the display front case 15, and fixed to the display front case 15; and a conduction part 59 which extends from the base 53 on the mounting plane 27a, and contacts the ground layer 27g.