The authors have developed a new passive flux sampler (PFS), which was a simple device to determine emission fluxes of potential biomarkers such as acetaldehyde and acetone emanating from the surface of the human skin. The sampler was placed on the skin surface to create a headspace. Within the space, gases emanating from skin moved toward the trapping filter (DNPH impregnated filter) by molecular diffusion and the trapped carbonyls were subsequently determined by HPLC. The PFS was practically applied to volunteers. The emission flux varies with sampling positions, probably depending on the different emanation routes. Personal emission flux also showed great variations between individuals.