To provide a liquid jetting apparatus which can absorb the thermal expansion portion of a supporting member when the supporting member for supporting a target is heated and thermally expanded.

An inkjet type printer is equipped with a platen 48, a recording head, a supporting mechanism and a heating apparatus. In this case, the platen 48 supports a long-sized continuous paper which is carried from the upstream side. The recording head jets an ink to the continuous paper which is supported by the platen 48. The supporting mechanism supports the platen 48. The heating apparatus heats the platen 48. The supporting mechanism includes a first supporting mechanism and a second supporting mechanism. In this case, the first supporting mechanism comes into contact with the platen 48 from the lower side, and at the same time, supports the platen 48 in such a manner that the thermal expansion of the platen 48 in the horizontal direction may be allowed. The second supporting mechanism comes into contact with the platen 48 from the upper side, and at the same time, supports the platen 48 in such a manner that the thermal expansion of the platen 48 in the horizontal direction may be allowed.