A portable telephone and electronic device are provided. The portable telephone includes a casing having a first surface: a finger guide section that is provided in the first surface and guides a finger of a user to allow the finger to be placed so that a side portion of the finger faces the first surface; an illuminating section provided in the first surface so as to be adjacent to the finger guide section, the illuminating section being capable of radiating light of a predetermined wavelength that transmits through the placed finger; an imaging section provided in the casing so as to be spaced at a predetermined distance from the first surface with respect to a perpendicular direction, the imaging section being capable of imaging the light that has transmitted through the finger; and a control section that performs authentication of the user on the basis of an image obtained by the imaging.