Resorcinol/formaldehyde (RF) foam resin is an attractive material as a low–density target in high power laser plasma experiments because of its fine network structure, transparency in the visible region, and low Z element (hydrogen, carbon, and oxygen) composition. In this study, we developed disk–shaped RF foam and deuterated RF foam targets with from 40 µm to 200 µm thickness and ~100 mg/cc density having a network structure from 100 nm to a few µm cell size. By deuteration, the polymerization rate was drastically slowed down due to kinetic isotope effects. These targets were used in high power laser experiments where a MeV proton beam was successfully generated.