PROBLEM TO BE SOLVED: To provide a paddy field working machine capable of feeding an agricultural material to a farm field uniformly regardless of the travel speed of a traveling machine body.SOLUTION: A paddy field working machine comprises a fertilizing device for feeding fertilizer to a farm field. The fertilizing device comprises a hopper for storing the fertilizer, and a delivery mechanism for delivering the fertilizer stored in the hopper. The delivery mechanism comprises: a delivery roll in which a storage part capable of temporarily storing the fertilizer stored in the hopper and then discharging the fertilizer to the farm field side is formed; a balance type drive mechanism for rotating the delivery roll on the basis of branch power branched from a transmission system for traveling; an adjustment mechanism capable of adjusting a preset amount of the fertilizer to be fed per unit area of the farm field; and an amount adjusting motor 47 capable of operating the adjustment mechanism. The farm field work
