A straddle-type vehicle comprising: a head pipe; a main frame being connected to the head pipe, extending rearward and obliquely downward from the head pipe; a left seat frame being connected to the main frame and comprising a left first portion (41 L) and a left second portion, the left first portion (41 L) extending rearward and obliquely downward from the main frame, and the left second portion formed integrally with the left first portion (41 L) and extending rearward and obliquely upward from the left first portion (41 L); a right seat frame being connected to the main frame and comprising a right first portion (41 R) and a right second portion, the right first portion (41 R) extending rearward and obliquely downward from the main frame, and the right second portion formed integrally with the right first portion (41 R) and extending rearward and obliquely upward from the right first portion (41 R), the right seat frame being disposed rightward of the left seat frame; a left down frame, being connected to the left first portion (41 L) of the left seat frame, being thinner than the left seat frame; a right down frame, being connected to the right first portion (41 R) of the right seat frame, being disposed rightward of the left down frame, and being thinner than the right seat frame; a seat supported by the left seat frame and the right seat frame; a body cover being provided over at least one side of each of the left seat frame and the right seat frame, and including an upper surface portion being located rearward of the head pipe and frontward of the seat and extending rearward and obliquely downward to a position downward relative to the seat; an engine disposed below the left down frame and the right down frame and supported by the left down frame and the right down frame; and an air cleaner, characterized in that the main frame has a rectangular cross-sectional shape; the left down frame extends rearward and obliquely downward from the left seat frame, the right down frame extends rearward and obliquely downward from the right seat frame, the air cleaner is disposed rearward relative to at least a portion of the engine and disposed between the left seat frame and the right seat frame and between the left down frame and the right down frame, wherein the left down frame extends inward in a vehicle lateral direction from the left first portion (41 L) of the left seat frame; a rear end portion of the left down frame is positioned between the left seat frame and the right seat frame as viewed in plan of the vehicle; the right down frame extends inward in the vehicle lateral direction from the right first portion (41 R) of the right seat frame; and a rear end portion of the right down frame is positioned between the left seat frame and the right seat frame as viewed in plan of the vehicle. a head pipe; a main frame being connected to the head pipe, extending rearward and obliquely downward from the head pipe; a left seat frame being connected to the main frame and comprising a left first portion (41 L) and a left second portion, the left first portion (41 L) extending rearward and obliquely downward from the main frame, and the left second portion formed integrally with the left first portion (41 L) and extending rearward and obliquely upward from the left first portion (41 L); a right seat frame being connected to the main frame and comprising a right first portion (41 R) and a right second portion, the right first portion (41 R) extending rearward and obliquely downward from the main frame, and the right second portion formed integrally with the right first portion (41 R) and extending rearward and obliquely upward from the right first portion (41 R), the right seat frame being disposed rightward of the left seat frame; a left down frame, being connected to the left first portion (41 L) of the left seat frame, being thinner than the left seat frame; a right down frame, being connected to the right first portion (41 R) of the right seat frame, being disposed rightward of the left down frame, and being thinner than the right seat frame; a seat supported by the left seat frame and the right seat frame; a body cover being provided over at least one side of each of the left seat frame and the right seat frame, and including an upper surface portion being located rearward of the head pipe and frontward of the seat and extending rearward and obliquely downward to a position downward relative to the seat; an engine disposed below the left down frame and the right down frame and supported by the left down frame and the right down frame; and an air cleaner, characterized in that the main frame has a rectangular cross-sectional shape; the left down frame extends rearward and obliquely downward from the left seat frame, the right down frame extends rearward and obliquely downward from the right seat frame, the air cleaner is disposed rearward relative to at least a portion of the engine and disposed between the left seat frame and the right seat frame and between the left down frame and the right down frame, wherein the left down frame extends inward in a vehicle lateral direction from the left first portion (41 L) of the left seat frame; a rear end portion of the left down frame is positioned between the left seat frame and the right seat frame as viewed in plan of the vehicle; the right down frame extends inward in the vehicle lateral direction from the right first portion (41 R) of the right seat frame; and a rear end portion of the right down frame is positioned between the left seat frame and the right seat frame as viewed in plan of the vehicle.