A bacterium producing ${alpha}$-galactosidase (${alpha}$-$small{D}$-galactoside galactohydrolase, EC 3.2.1.22) was isolated. The isolate, KM-1 was identified as Bacillus coagulans based on its 16S rRNA sequence, morphology, and biochemical properties. ${alpha}$-Galactosidase activity was detected the culture supernatant of B. coagulans KM-1. The bacterium showed the maximum activity for hydrolyzing para-nitrophenyl-${alpha}$-$small{D}$-galactopyranoside (pNP-${alpha}Gal$) at pH 6.0 and $50^{circ}C$. It hydrolyzed oligomeric substrates such as melibiose, raffinose, and stachyose liberating a galactose residue, indicating that the B. coagulans KM-1 ${alpha}$-galactosidase hydrolyzed ${alpha}$-1,6 linkage. The results suggest that the decreased stachyose and raffinose contents in fermented soybean meal are due to the ${alpha}$-galactosidase activity.