This work presents an empirical indoor sub-THz channel characterization. The frequency aspect is studied through measurement campaigns conducted for different frequency ranges: 125–155 GHz, 235–265 GHz and 270–300 GHz, allowing to compare the channel of the D-band range with the channel above 200 GHz. Two different laboratory scenarios are taken into account. A double steering of the antennas at the transmitting and receiving side allows to perform a double angular characterization. The multipath components detection results are provided and path loss and delay spread models are reported. Finally, a clustering of the detected paths is also presented.