A cowl structure that is small in size and light, and that is effective in preventing air discharged from a radiator from being applied to the legs of the rider. An upper cowl includes ridges projecting laterally outwardly in the transverse direction of the vehicle, slanted surfaces extending from the ridges in the forward direction of the vehicle and directed toward the center of the vehicle, and rear slanted surfaces extending from the ridges in a rearward direction of the vehicle and directed toward the center of the vehicle. The air discharged from the radiator is not applied to the legs of the rider. Since the action is achieved simply by deforming the upper cowl, the cowl can be reduced in size and weight.