The supporting particles with curdlan, activated carbon and Hwangtoh(Yellow Ochre) were developed to immobilize microbial cells. For the twelve different particles, the iron oxidation rates were measured to determined the appropriate supporting particles. With flask culture, pH was slightly decreased from initial pH 1.95 to pH 1.6 after iron oxidation. Iron oxidation rate was increased almost 100 % more with supporting particles with 20 g/L of curdlan, 200 g/L of Hwangtoh(Yellow Ochre), and 2 g/L of activated carbon than without supporting particles. With protein assay, we found that cells were immobilized on the immobilized particles.