A straddle-type vehicle comprising: an exhaust device in which an exhaust passage wraps around from a front side of an engine of the straddle-type vehicle to a lower side of the engine and extends to a rear side, the exhaust device including: a catalyst configured to purify exhaust gas in the exhaust passage and disposed in front of the engine; and a gas sensor disposed on a wall surface of the exhaust passage at an upstream side than the catalyst, wherein the gas sensor is disposed in front of the engine so as to be directed toward the engine, the engine is assembled to a vehicle body frame, the gas sensor overlaps a down tube that extends downward from a head pipe of the vehicle body frame in a side view, the exhaust device includes an additional gas sensor disposed on the wall surface of the exhaust passage at a downstream side from the catalyst, the additional gas sensor overlaps the down tube in the side view, and the straddle-type vehicle is characterized in that the down tube includes an upper down tube extending downward from the head pipe in a center of the engine in the left-right direction, and a pair of lower down tubes (15L, 15R) branching left and right from a lower end of the upper down tube and extending downward, and the additional gas sensor is disposed between the pair of lower down tubes (15L, 15R), and the additional gas sensor overlaps the pair of lower down tubes (15L, 15R) in the side view. an exhaust device in which an exhaust passage wraps around from a front side of an engine of the straddle-type vehicle to a lower side of the engine and extends to a rear side, the exhaust device including: a catalyst configured to purify exhaust gas in the exhaust passage and disposed in front of the engine; and a gas sensor disposed on a wall surface of the exhaust passage at an upstream side than the catalyst, wherein a catalyst configured to purify exhaust gas in the exhaust passage and disposed in front of the engine; and a gas sensor disposed on a wall surface of the exhaust passage at an upstream side than the catalyst, wherein the gas sensor is disposed in front of the engine so as to be directed toward the engine, the engine is assembled to a vehicle body frame, the gas sensor overlaps a down tube that extends downward from a head pipe of the vehicle body frame in a side view, the exhaust device includes an additional gas sensor disposed on the wall surface of the exhaust passage at a downstream side from the catalyst, the additional gas sensor overlaps the down tube in the side view, and the straddle-type vehicle is characterized in that the down tube includes an upper down tube extending downward from the head pipe in a center of the engine in the left-right direction, and a pair of lower down tubes (15L, 15R) branching left and right from a lower end of the upper down tube and extending downward, and the additional gas sensor is disposed between the pair of lower down tubes (15L, 15R), and the additional gas sensor overlaps the pair of lower down tubes (15L, 15R) in the side view. the down tube includes an upper down tube extending downward from the head pipe in a center of the engine in the left-right direction, and a pair of lower down tubes (15L, 15R) branching left and right from a lower end of the upper down tube and extending downward, and the additional gas sensor is disposed between the pair of lower down tubes (15L, 15R), and the additional gas sensor overlaps the pair of lower down tubes (15L, 15R) in the side view.