A liquid jetting apparatus includes: a liquid jetting head; a carriage which carries the liquid jetting head and moves in a scanning direction; a plurality of pulleys arranged on a first plane, each having an axis extending perpendicular to the first plane, and including at least a first pulley and a second pulley separated from the first pulley in the scanning direction; an endless belt put around the plurality of pulleys to make contact with a circumference of each of the first and second pulleys and connected to the carriage; a pulley holder having a fixing portion, holding a tension adjusting pulley which adjusts a tension applied to the belt, being movable along the first plane together with the tension adjusting pulley; two plates sandwiching the fixing portion of the pulley holder; and a fastening member which fixes the fixing portion to the two plates.