There is provided a first substrate having a first main surface, a second substrate having a second main surface, a bonding member bonding the first main surface and the second main surface, and a flow path positioned between the first substrate and the second substrate and extended in a parallel direction with the first main surface and the second main surface, and the bonding member has a projection which is protruded from a portion between the first main surface and the second main surface toward an inner part of the flow path, the flow path includes a first portion having the projection provided in an inner part and a second portion linked to the first portion adjacently to an opposite side to a side where the projection of the first portion is provided, and a height of the first substrate is greater than a height of the second portion in the thickness direction.