Due to the possibility of high Er³⁺ doping and their broadband emission, the bithmuth-oxide-based glasses can be a promising candidate of host materials for a compact waveguide amplifier with high performance. By a novel fabrication process, we have developed a Bi₂O₃-based waveguide device with propagation loss as low as 0.13 dB/cm, which is comparable to the silica-based waveguides. We have achieved an ultra-compact Er-doped waveguide amplifier with 1 cm² size by designing a spiral light-wave circuit with low bending loss. This EDWA showed gain values over 15 dB, noise figures lower than 8 dB and gain flatness less than 2 dB over the whole C-band region. The output power of this EDWA reached higher than 12 dBm.