There is provided an air cleaner configured to be disposed inside a vehicle body frame, the air cleaner including: an air cleaner case in which an intake chamber is formed; an air filter disposed in the intake chamber; an inlet tube configured to take in air to the intake chamber; and an outlet tube configured to send out the air from the intake chamber. The inlet tube extends in a front-rear direction. The inlet tube has a bottom wall curved downward in a side view to form a concave curved portion below a discharge port of the inlet tube. The concave curved portion is formed with a drain hole.