PROBLEM TO BE SOLVED: To provide an electrically driven riding mower capable of keeping the reaping height constant regardless of the geographical features, and capable of discharging reaped grass into one direction.SOLUTION: The electrically driven riding mower is equipped with a mower blade for reaping the grass by being rotated, nearly deep dish-like mower decks 15A and 15B covering the mower blade from upper and side directions, mower motors 20 and 20 arranged on the mower decks 15A and 15B, and attached to a rotary shaft of the mower blade, assistant wheels attached to the out sides of the front parts of the mower decks 15A and 15B, and for detecting the bulge of the traveling face, and a subframe 55 extended in the advancing direction and for supporting the mower decks 15A and 15B. The mower decks 15A and 15B are installed in the right and left of the subframe 55 respectively, and the subframe 55 supports the mower decks 15A and 15B so as to be turnable sideward in the upper and lower direction. Notches are formed at side parts of the facing sides of the right and left mower decks 15A and 15B respectively, and the mower deck unit 15 is formed by connecting the two mower decks 15A and 15B by a flexible deck cover DC.COPYRIGHT: (C)2012,JPO&INPIT【課題】地形によらず刈高さを一定に保つとともに、刈り取った草を一方向に排出可能な電動乗用草刈機を提供する。【解決手段】回転して草を刈るモアブレードと、モアブレードを上方および側方から覆う略深皿状のモアデッキ15A,15Bと、モアデッキ15A,15B上に配置されるとともに、モアブレードの回転軸に取り付けられたモアモータ20,20と、モアデッキ15A,15Bの前部外側に取り付けられ、走行面の隆起を検出するための補助車輪と、前進方向に延設され、モアデッキ15A,15Bを支持するサブフレーム55とを備え、モアデッキ15A,15Bは、サブフレーム55の左右にそれぞれ設けられ、サブフレーム55は、モアデッキ15A,15Bを側方に向けて上下回動可能に支持し、左右のモアデッキ15A,15Bの向かい合う側の側部にそれぞれ切り欠きを設けるとともに、2つのモアデッキ15A,15Bを柔軟性のあるデッキカバーDCで連結して、モアデッキユニット15を形成する。【選択図】図6