A straddle vehicle having an under bone frame structure in which a portion positioned in front of a seat is recessed downward. An air cleaner is disposed behind a cylinder block of an engine to be interposed between a right and a left seat rail. An upper portion of the air cleaner projects upward more than the seat rails. A top of the air cleaner is covered by a seat front cover that divides a space defined in front of the seat. The air cleaner includes a lid and a cleaner case that is more tall than is broad. For maintenance work, the seat front cover is removed, and the lid is taken out obliquely upward forward.