FUEL TANK FOR STRADDLE TYPE VEHICLE

To provide a fuel tank of a straddle type vehicle, whose die for bending a body can be drawn easily, and whose knee grip part can be formed easily. A body 85 is formed by integrally joining, at the center in the vehicle width direction, body half bodies divided into two in the vehicle width direction, a body flange 85b to be placed on and welded to a bottom 87, is formed on the entire outer circumferential edge of the body 85, a rear part (specifically, a rear lateral welding portion 89r side) of a side part (lateral welding portion 89b side) of the body flange 85b protrudes inward in the vehicle width direction toward the obliquely lower direction, and a part of the side part other than the rear part (specifically, a front lateral welding portion 89f side) of the body flange 85b protrudes inward in the vehicle width direction toward the obliquely upper direction.