Speciation of iron (Fe) precipitated on bacterial stalks was studied by Fe K-edge mu-XRF-XAFS. Micro-XRF analysis of the stalk samples showed that Fe is precipitated around the stalk. All the mu-XANES spectra at several Fe-accumulated parts showed similar spectra. This study indicated that synchrotron mu-XRF-XAFS is a powerful tool for chemical speciation of metals at single-cell level for bacteria bearing metal.