An emitter configured to be joined on an inner wall surface of a tube for carrying irrigation liquid at a position corresponding to a discharging port communicating between inside and outside of the tube, the emitter being configured to quantitatively discharge the irrigation liquid in the tube from the discharging port to the outside of the tube, the emitter comprising: a water intake part for intake of the irrigation liquid in the tube; a first pressure reduction channel part for forming a first pressure reduction channel configured to allow the irrigation liquid received at the water intake part to flow therethrough while reducing a pressure of the irrigation liquid received at the water intake part; a discharge rate adjusting part for controlling a flow rate of the irrigation liquid supplied from the first pressure reduction channel in accordance with a pressure of the irrigation liquid in the tube; a discharging part for housing the irrigation liquid supplied from the discharge rate adjusting part, the discharging part being configured to face the discharging port; and a communication channel part configured to communicate between the discharge rate adjusting part and the discharging part, wherein the discharge rate adjusting part includes: a recess, a film having flexibility, the film being disposed such that the film is separated from the recess and is capable of making close contact with the recess when the pressure of the irrigation liquid in the tube is equal to or greater than a set value, a supply port communicated with the first pressure reduction channel part and configured to supply the irrigation liquid to the recess, a first hole opening at the recess and the discharging part and configured to be sealed with the film when the film makes close contact with the recess, a second hole opening at the communication channel part and at a position where the second hole is communicated with the supply port when the film seals the first hole, and a groove formed on a surface of the recess and configured to directly communicate between the supply port and the second hole, the communication channel part includes a second pressure reduction channel part for forming a second pressure reduction channel configured to allow the irrigation liquid to flow therethrough while reducing the pressure of the irrigation liquid, in plan view, the groove is formed along a longer arc of a circle around an edge of the first hole, the longer arc extending between the supply port and the second hole. a water intake part for intake of the irrigation liquid in the tube; a first pressure reduction channel part for forming a first pressure reduction channel configured to allow the irrigation liquid received at the water intake part to flow therethrough while reducing a pressure of the irrigation liquid received at the water intake part; a discharge rate adjusting part for controlling a flow rate of the irrigation liquid supplied from the first pressure reduction channel in accordance with a pressure of the irrigation liquid in the tube; a discharging part for housing the irrigation liquid supplied from the discharge rate adjusting part, the discharging part being configured to face the discharging port; and a communication channel part configured to communicate between the discharge rate adjusting part and the discharging part, wherein the discharge rate adjusting part includes: a recess, a film having flexibility, the film being disposed such that the film is separated from the recess and is capable of making close contact with the recess when the pressure of the irrigation liquid in the tube is equal to or greater than a set value, a supply port communicated with the first pressure reduction channel part and configured to supply the irrigation liquid to the recess, a first hole opening at the recess and the discharging part and configured to be sealed with the film when the film makes close contact with the recess, a second hole opening at the communication channel part and at a position where the second hole is communicated with the supply port when the film seals the first hole, and a groove formed on a surface of the recess and configured to directly communicate between the supply port and the second hole, a recess, a film having flexibility, the film being disposed such that the film is separated from the recess and is capable of making close contact with the recess when the pressure of the irrigation liquid in the tube is equal to or greater than a set value, a supply port communicated with the first pressure reduction channel part and configured to supply the irrigation liquid to the recess, a first hole opening at the recess and the discharging part and configured to be sealed with the film when the film makes close contact with the recess, a second hole opening at the communication channel part and at a position where the second hole is communicated with the supply port when the film seals the first hole, and a groove formed on a surface of the recess and configured to directly communicate between the supply port and the second hole, the communication channel part includes a second pressure reduction channel part for forming a second pressure reduction channel configured to allow the irrigation liquid to flow therethrough while reducing the pressure of the irrigation liquid, in plan view, the groove is formed along a longer arc of a circle around an edge of the first hole, the longer arc extending between the supply port and the second hole.