A flow path unit includes a pressure chamber substrate in which a plurality of pressure chambers are arranged in a first direction; and a piezoelectric element that changes a volume of the pressure chamber, in which a plane shape of an active section of the piezoelectric element is contained such that a width on one side thereof in a second direction crossing the first direction is wider than that on the other side in the second direction. The side on which the width of the active section of the piezoelectric element is great and the side on which the width thereof is smaller in the second direction be alternately disposed each other so that the active sections adjacent to each other are arranged differently from each other in the first direction.