The influence of the titania photocatalyst particle of the nanometer region on the human being and biology’s to be doubted. Removing the uneasiness will expand further uses for the photocatalyst nanoparticle. Then, we attempted to examine the effect of several titania photocatalyst nanoparticles to the artificial skin like the human body under the UV and visible light irradiation conditions. The decomposition degree of the artificial skin was evaluated from the monitoring of the amount of carbon dioxide generated from them by the titania photocatalyst nanoparticle activity. Under the UV irradiation condition, it was almost found the carbon dioxide emergence from the artificial skin by the activity of the titania photocatalyst nanoparticle. On the other hand, under visible light condition it was mostly detected.