A portable body fat measurement device includes: a light source unit having at least two top view light sources and a guide unit perpendicularly guiding an optical signal generated in the top view light sources to determine a measurement point where body fat is measured; an optical detection unit detecting a scattered optical signal to transform into an electrical signal, the scattered optical signal being generated by a scattering of the optical signal irradiated to the measurement point; and a signal processing unit processing the electrical signal and calculating body fat information, wherein the at least two top view light sources and the optical detection unit are horizontally arranged.