A loom including a drive transmission shaft connected to a warp beam via a gear member inside a loom frame and inserted in a through-hole formed in a side frame, and a support structure for supporting the drive transmission shaft, the support structure including a first bearing and a second hearing externally fitted to the drive transmission shaft at an interval in an axis line direction. The support structure includes a first bearing case configured to accommodate therein the first bearing and attached to the side frame inside the loom frame and a second bearing case configured to accommodate therein the second bearing and attached to the side frame outside the loom frame.