PROBLEM TO BE SOLVED: To provide a reaping portion elevation control device of reaping harvester, which performs an excellent reaping operation by carrying out a proper reaping portion elevation control according to difference in operation conditions such as paddy field condition, planted condition of reaping object grain culms, etc.SOLUTION: A control means for carrying out a reaping portion elevation control for controlling an elevation operation means on the basis of information of a plurality of grounded type ground height detection means disposed at different parts in the reaping direction in a reaping part and a target ground height set means changes a rise treatment mode in detection of small number in which the reaping part rises when any one of two ground height detection means detects a value lower than a target ground height to a rise treatment mode in detection of a large number in which the reaping part rises when all the ground height detection means detects a value lower than the target ground height on the basis of the order of a manual operation type control mode change order means.COPYRIGHT: (C)2010,JPO&INPIT【課題】圃場面の状況や刈取対象穀稈の植立状態等の作業状況の違いに応じて適切な刈取昇降制御を行うことにより、良好な刈取作業を行うことが可能となる刈取収穫機の刈取昇降制御装置を提供する。【解決手段】刈取部における刈幅方向の異なる箇所に配備された複数の接地式の対地高さ検出手段及び目標対地高さ設定手段の情報に基づいて昇降操作手段を制御する刈取昇降制御を実行する制御手段が、手動操作式の制御モード切換指令手段の指令に基づいて、2個の対地高さ検出手段のいずれかが目標対地高さよりも低い値を検出すると刈取部を上昇させる少数検出時上昇処理モードと、全ての対地高さ検出手段が目標対地高さよりも低い値を検出すると刈取部を上昇させる多数検出時上昇処理モードとを切り換える。【選択図】図9