The present invention relates to: a process for producing D-serine wherein a microbial cell which is modified to have a higher L-serine deaminase activity than Escherichia coli DH5α strain, a culture of said cell, or a processed product thereof is brought into contact with DL-serine in a DL-serine-containing medium to decompose L-serine, and the remaining D-serine is recovered from the medium; and a microorganism used for this production process. D-serine is a useful compound as a synthetic intermediate for useful medicaments such as D-cycloserine.