A method of manufacturing a head chip which has an actuator plate, and is adapted to apply pressure to a liquid with the actuator plate so as to jet the liquid, the method comprising: manufacturing the actuator plate; and joining a nozzle plate having a jet hole for the liquid to a surface (411E3) of the actuator plate, wherein the manufacturing the actuator plate includes preparing a piezoelectric substrate which has one end (411E1) and another end (411E2) at an opposite side to the one end, and has a first groove (C1e) extending in a groove extending direction from the one end side toward the other end, and to be communicated with the jet hole, and a second groove (C1d) extending in the groove extending direction on at least at one side of the first groove in a direction crossing the groove extending direction, providing a conductive film to a surface of the piezoelectric substrate, and performing laser processing in the groove extending direction on the conductive film between the first groove and the second groove so as to form a laser processing area where the conductive film is removed to the surface of the piezoelectric substrate between the first groove and the second groove, and in the forming the laser processing area, an irradiation operation with a laser is performed along a plurality of laser processing lines (L1, L2, L3) extending in the groove extending direction; the method of manufacturing the head chip is characterised in that the irradiation operation with the laser is performed a plurality of times (a1-a6) for each of the laser processing lines, wherein the plurality of laser processing lines are placed between the first groove and the second groove, and the irradiation operations with the laser performed along the same laser processing line of the plurality of laser processing lines are performed at a time interval from when ending a previous irradiation operation with the laser to when starting a subsequent irradiation operation with the laser. manufacturing the actuator plate; and joining a nozzle plate having a jet hole for the liquid to a surface (411E3) of the actuator plate, wherein the manufacturing the actuator plate includes preparing a piezoelectric substrate which has one end (411E1) and another end (411E2) at an opposite side to the one end, and has a first groove (C1e) extending in a groove extending direction from the one end side toward the other end, and to be communicated with the jet hole, and a second groove (C1d) extending in the groove extending direction on at least at one side of the first groove in a direction crossing the groove extending direction, providing a conductive film to a surface of the piezoelectric substrate, and performing laser processing in the groove extending direction on the conductive film between the first groove and the second groove so as to form a laser processing area where the conductive film is removed to the surface of the piezoelectric substrate between the first groove and the second groove, and preparing a piezoelectric substrate which has one end (411E1) and another end (411E2) at an opposite side to the one end, and has a first groove (C1e) extending in a groove extending direction from the one end side toward the other end, and to be communicated with the jet hole, and a second groove (C1d) extending in the groove extending direction on at least at one side of the first groove in a direction crossing the groove extending direction, providing a conductive film to a surface of the piezoelectric substrate, and performing laser processing in the groove extending direction on the conductive film between the first groove and the second groove so as to form a laser processing area where the conductive film is removed to the surface of the piezoelectric substrate between the first groove and the second groove, and in the forming the laser processing area, an irradiation operation with a laser is performed along a plurality of laser processing lines (L1, L2, L3) extending in the groove extending direction; the method of manufacturing the head chip is characterised in that the irradiation operation with the laser is performed a plurality of times (a1-a6) for each of the laser processing lines, wherein the plurality of laser processing lines are placed between the first groove and the second groove, and the irradiation operations with the laser performed along the same laser processing line of the plurality of laser processing lines are performed at a time interval from when ending a previous irradiation operation with the laser to when starting a subsequent irradiation operation with the laser. an irradiation operation with a laser is performed along a plurality of laser processing lines (L1, L2, L3) extending in the groove extending direction; the method of manufacturing the head chip is characterised in that the irradiation operation with the laser is performed a plurality of times (a1-a6) for each of the laser processing lines, wherein the plurality of laser processing lines are placed between the first groove and the second groove, and the irradiation operations with the laser performed along the same laser processing line of the plurality of laser processing lines are performed at a time interval from when ending a previous irradiation operation with the laser to when starting a subsequent irradiation operation with the laser.