A horizontal band saw machine includes a pair of jaws, a pair of saw blade wheels, a band saw blade looped over the saw blade wheels, a pair of saw blade guides, a contact guide attached to the other of the pair of jaws, a coupling bracket connected to the other of the pair of saw blade guides to locate a distal end thereof below the other of the pair of saw blade wheels, and a follower member provided at the distal end of the coupling bracket. The contact guide and the coupling bracket are configured to move one of the pair of saw blade guides until the follower member contacts with the contact guide when the band saw blade is fed circularly in a state where the band saw blade is clamped by the one of the pair of saw blade guides.