A recombinant microorganism obtained by transferring, into a host microorganism capable of producing protein or polypeptide with increased productivity, a gene encoding a protein or polypeptide, and a method for producing a protein or polypeptide by use of the recombinant microorganism. The recombinant microorganism is prepared by transferring, to a mutant strain of microorganism from which any of Bacillus subtilis genes comA, yopO, treR, yvbA, cspB, yvaN, yttP, yurK, yozA, licR, sigL, mntR, glcT, yvdE, ykvE, sir, rocR, ccpA, yaaT, yyaA, yycH, yacP, hprK, rsiX, yhdK, and yibO, or one or more genes functionally equivalent to any of these genes have been deleted or knocked out, a gene encoding a heterologous protein or polypeptide.