A lawn mower includes a mower deck including a blade rotationally driven to cut grass and generate an air flow to feed the cut grass. A cutting chamber houses the blade. An ejection outlet is open to the cutting chamber and ejects the cut grass. A grass collection container collects the cut grass ejected from the ejection outlet. An air chamber is provided in a vicinity of the cutting chamber and receives the air flow generated by rotation of the blade through the grass collection container. A first passage connects the ejection outlet and the grass collection container. A second passage connects the grass collection container and the air chamber. The air flow supplied from the grass collection container to the air chamber through the second passage is supplied to the cutting chamber.