It has been reported that using fluorescent nanodiamonds (NDs) with nitrogen vacancy (NV) centers enables to obtain various environmental physical information in the nano region such as electric filed, magnetic field and so on. This technology is based on the decrease in the fluorescence intensity caused by the magnetic resonance between the electron at the NV center and microwaves. The method is called the optically detected magnetic resonance (ODMR). In particular, the fluorescent NDs act as the temperature nanosensors using temperature dependence of the ODMR frequency caused by lattice expansion. In order to measure ODMR inside biological samples, we have developed an ODMR measurement device that incorporates the coplanar antenna and then we have succeeded in detecting ODMR signals inside biological samples.