This drip-irrigation device has plate-shaped inflow parts, an emission-rate control part, and a first groove section. The long direction of each inflow part is parallel to the lengthwise direction of a circulation tube that has a bottom surface joined to the inside surface thereof and a top surface opposite said bottom surface. The inflow parts are laid out on said top surface and cause an irrigation liquid inside the circulation tube to flow into channels. The emission-rate control part controls the rate with which said irrigation liquid is emitted, via the channels, from emission holes. The first groove section is formed as a recess in the aforementioned top surface, from one lengthwise end thereof towards the other lengthwise end, and is shaped such that the width and depth thereof gradually decrease with decreasing distance from said other lengthwise end.
