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.