A saddle type vehicle comprising: a handlebar unit provided forward of a seat in a vehicle forward/rearward direction, the seat held by a vehicle body frame; a left grip portion and a right grip portion respectively provided on a left end portion and a right end portion of the handlebar unit; and an input device provided to the handlebar unit, the input device configured to be operable with a palmar side of a thumb of a hand gripping one of the left grip portion and the right grip portion; the input device comprises: a case; and a rotating body which is a disc-like member including an operational surface arranged in a circumferential direction, the operational surface extends continuously along the entire circumference of the rotating body without interruption, and includes a portion which is accommodated in the case wherein a remaining portion of the operational surface is exposed to an outside of the case, wherein the entire operational surface forms the surface operable by the thumb, the rotating body being disposed so as to be rotatable about an axis (Cr) which passes through the center of the rotating body, crosses the longitudinal direction of the corresponding one of the grip portions (8a, 8b) and extends, in use, in a direction orthogonal to (i) a thumb thickness direction (TB, TC) and (ii) a nail length direction of the thumb (LB, LC) which is of the hand gripping the corresponding one of the grip portions (8a, 8b) and is in contact with the portion of the operational surface which is exposed to the outside of the case, the rotating body is configured to be rotationally operated by flexing and/or extending the thumb of the hand gripping the corresponding one of the grip portions (8a, 8b) while the palmar side of the thumb is in contact with the portion of the operational surface which is exposed to the outside of the case so that the thumb thickness direction (TB, TC) and the nail length direction of the thumb (LB, LC) respectively extend in directions orthogonal to the axis (Cr). a handlebar unit provided forward of a seat in a vehicle forward/rearward direction, the seat held by a vehicle body frame; a left grip portion and a right grip portion respectively provided on a left end portion and a right end portion of the handlebar unit; and an input device provided to the handlebar unit, the input device configured to be operable with a palmar side of a thumb of a hand gripping one of the left grip portion and the right grip portion; the input device comprises: a case; and a rotating body which is a disc-like member including an operational surface arranged in a circumferential direction, the operational surface extends continuously along the entire circumference of the rotating body without interruption, and includes a portion which is accommodated in the case wherein a remaining portion of the operational surface is exposed to an outside of the case, wherein the entire operational surface forms the surface operable by the thumb, the rotating body being disposed so as to be rotatable about an axis (Cr) which passes through the center of the rotating body, crosses the longitudinal direction of the corresponding one of the grip portions (8a, 8b) and extends, in use, in a direction orthogonal to (i) a thumb thickness direction (TB, TC) and (ii) a nail length direction of the thumb (LB, LC) which is of the hand gripping the corresponding one of the grip portions (8a, 8b) and is in contact with the portion of the operational surface which is exposed to the outside of the case, the rotating body is configured to be rotationally operated by flexing and/or extending the thumb of the hand gripping the corresponding one of the grip portions (8a, 8b) while the palmar side of the thumb is in contact with the portion of the operational surface which is exposed to the outside of the case so that the thumb thickness direction (TB, TC) and the nail length direction of the thumb (LB, LC) respectively extend in directions orthogonal to the axis (Cr). a case; and a rotating body which is a disc-like member including an operational surface arranged in a circumferential direction, the operational surface extends continuously along the entire circumference of the rotating body without interruption, and includes a portion which is accommodated in the case wherein a remaining portion of the operational surface is exposed to an outside of the case, wherein the entire operational surface forms the surface operable by the thumb, the rotating body being disposed so as to be rotatable about an axis (Cr) which passes through the center of the rotating body, crosses the longitudinal direction of the corresponding one of the grip portions (8a, 8b) and extends, in use, in a direction orthogonal to (i) a thumb thickness direction (TB, TC) and (ii) a nail length direction of the thumb (LB, LC) which is of the hand gripping the corresponding one of the grip portions (8a, 8b) and is in contact with the portion of the operational surface which is exposed to the outside of the case, the rotating body is configured to be rotationally operated by flexing and/or extending the thumb of the hand gripping the corresponding one of the grip portions (8a, 8b) while the palmar side of the thumb is in contact with the portion of the operational surface which is exposed to the outside of the case so that the thumb thickness direction (TB, TC) and the nail length direction of the thumb (LB, LC) respectively extend in directions orthogonal to the axis (Cr).