A multiple spindle drilling machine for wide flange beams comprising a guide member vertically movably disposed on a gear box, drills disposed on the guide member in two upper and lower lines, said drills being arranged so that when they are moved and brought close to a wide flange beam together with the gear box, flanges of the wide flange beam are drilled, sensing means having the top end capable of bearing against the web surface of the wide flange beam and attached to a part of the guide member, and a centering device for vertically moving said sensing means together with the guide member and stopping said vertical movement when the sensing means bears against the web surface of the wide flange beam, so that the central position between the two lines of the drills is made in agreement with the central position of the thickness direction of the web of the wide flange beam.