My research interest is to investigate extrasolar planets and life on them. We conduct observational research to investigate formation process of extrasolar planets as well as galaxy formation and starburst phenomena. In these astronomical phenomena, small solid particles (interstellar dust grains) play important roles in energy conversion and various chemical reactions in space. As the dust grains reradiate absorbed energy mainly as infrared radiation, precise infrared observations provide us valuable information to elucidate important physical processes in space. The longer wavelength part of infrared (far-infrared) cannot be observed from the ground because the earth's atmosphere is completely opaque. Therefore, we mount the far-infrared telescopes on artificial satellites and scientific balloons, and execute precise observations in space. In particular, we are developing a far-infrared astronomical interferometer for the first time in the world so as to achieve a spatial resolution more than ten times higher than previously obtained. We also perform near-infrared high-contrast observations of protoplanetary disks and young, gaseous giant extrasolar planets using the Subaru telescope in Hawaii.