A motorcycle , comprising: a vehicle body ; and a cowling structure provided to cover a front portion of the vehicle body , wherein the cowling structure includes a front cowling and a tubular portion constituting a passage through which the air flows, the tubular portion including: a front opening forming section formed with a front opening which opens to a front in the vehicle body ; a rear opening forming section formed with a rear opening which is placed rearward relative to the front opening and opens to a rear in the vehicle body ,; an inclined wall which is placed between a lower portion of the front opening forming section and a lower portion of the rear opening forming section , extends in a forward and rearward direction, and includes an inclined surface inclined to be higher as the inclined surface extends in a rearward direction; and an outer side wall protruding upward from an outer side portion of the inclined wall in a vehicle width direction of the vehicle body and extending in the forward and rearward direction characterized in that : the tubular portion further includes an inner side wall which is formed by an outer side portion of the front cowling , a rectangular cross-section formed with the front opening and the rear opening is formed by the inclined wall , the outer side wall , an upper wall , and the inner side wall . a vehicle body ; and a cowling structure provided to cover a front portion of the vehicle body , wherein the cowling structure includes a front cowling and a tubular portion constituting a passage through which the air flows, the tubular portion including: a front opening forming section formed with a front opening which opens to a front in the vehicle body ; a rear opening forming section formed with a rear opening which is placed rearward relative to the front opening and opens to a rear in the vehicle body ,; an inclined wall which is placed between a lower portion of the front opening forming section and a lower portion of the rear opening forming section , extends in a forward and rearward direction, and includes an inclined surface inclined to be higher as the inclined surface extends in a rearward direction; and an outer side wall protruding upward from an outer side portion of the inclined wall in a vehicle width direction of the vehicle body and extending in the forward and rearward direction a front opening forming section formed with a front opening which opens to a front in the vehicle body ; a rear opening forming section formed with a rear opening which is placed rearward relative to the front opening and opens to a rear in the vehicle body ,; an inclined wall which is placed between a lower portion of the front opening forming section and a lower portion of the rear opening forming section , extends in a forward and rearward direction, and includes an inclined surface inclined to be higher as the inclined surface extends in a rearward direction; and an outer side wall protruding upward from an outer side portion of the inclined wall in a vehicle width direction of the vehicle body and extending in the forward and rearward direction characterized in that : the tubular portion further includes an inner side wall which is formed by an outer side portion of the front cowling , a rectangular cross-section formed with the front opening and the rear opening is formed by the inclined wall , the outer side wall , an upper wall , and the inner side wall . the tubular portion further includes an inner side wall which is formed by an outer side portion of the front cowling , a rectangular cross-section formed with the front opening and the rear opening is formed by the inclined wall , the outer side wall , an upper wall , and the inner side wall . <EOS>