Provided is a rice transplanter that detects the surface of a field corrects deviations between the field ground contacting surface detected by a float and the actual field surface and detects an appropriate planting height thus preventing planting defects. The rice transplanter which is provided with a float that detects the field ground contacting surface is provided with a sensor that detects the field surface and that is provided separately from the float. The sensor has a detection unit which tracks the field surface and a support unit which supports the detection unit in a manner able to oscillate and the field surface height is detected by measuring the angle of oscillation of the detection unit when tracking the field surface.
