The present invention addresses the problem of reducing manufacturing cost of a group of models as a whole by facilitating common use of front axle cases and the like among rice- planting machine models having different treads between right and left wheels. This rice planting machine is equipped with: a traveling machine body (1) on which an engine (8) and a transmission case (9) are mounted and a rice- planting unit (4) that is attached in a liftable manner to the traveling machine body (1) via a linking mechanism (6). A pair of right and left front axle cases (10), which is located at an anterior part of the traveling machine body (1) ,is used to support front wheels (2). Rear axle cases (12), which are located at the posterior part of the traveling machine body (1) , are used to support rear wheels (3). The upper ends of the respective front axle cases (10) are attached to a machine frame (7) of the traveling machine body (1). The front axle cases (10) are connected to the machine frame (7) in such a manner that the spacing therebetween can be adjusted to increase or decrease in the horizontal direction.
