Provided is a rice planting machine that optimizes the trajectory of planting claws and prevents planting errors by applying torque that negates torque fluctuation occurring in a planting arm shaft levelling torque fluctuation and improving phase shift. The planting machine transmits dynamic force via a non uniform speed mechanism to a planting arm shaft that supports the rotary case and has provided therein a torque negating mechanism that applies torque that negates torque fluctuation caused by the non uniform speed mechanism. The torque negating mechanism has: a crank section wherein part of a planting vertical shaft that transmits dynamic force to the planting arm shaft is formed in a crank shape； and a spring attached to the crank section. Torque is applied by the spring.
