A droplet discharge device including a plurality of vibrators arranged on an upper surface of a substrate. The substrate has a cavity, discharge hole and supply hole, which serve as a liquid flow path, formed inside a plate including flat upper and lower surfaces. A width of the cavity narrows from the upper surface side toward the lower surface side. A depth of the cavity deepens from the supply hole side toward the discharge hole side. The depth of the cavity may become shallower from the supply hole side toward the discharge hole side in a part which is positioned on the supply hole side and occupies a relatively small area, and the depth of the cavity may become deeper from the supply hole side toward the discharge hole side in a part which is positioned on the discharge hole side and occupies a relatively large area.