A liquid jet head comprising: an actuator plate; a plurality of jet channels formed on the actuator plate, each of the jet channels extending lengthwise along a first direction and being filled with liquid; a plurality of dummy channels formed on the actuator plate, each of the dummy channels extending lengthwise along the first direction and not being filled with liquid; a jet hole plate laminated on the actuator plate and including a plurality of jet holes, each of the jet holes communicating with the corresponding one of the jet channels at a midway part in the first direction of the jet channel, wherein the actuator plate includes a first channel row including the jet channels and the dummy channels alternately arranged side by side in a second direction intersecting the first direction and a second channel row including the jet channels and the dummy channels alternately arranged side by side in the second direction, the first channel row and the second channel row being spaced apart from each other in the first direction, each of the jet channels is plane-symmetric with respect to a plane that passes through a center in the first direction of the jet channel, the plane being perpendicular to the first direction, the jet hole plate is configured to jet the liquid from the jet holes in a third direction perpendicular to the first direction and the second direction, the dummy channels of the first channel row and the dummy channels of the second channel row are open on respective end faces in the first direction of the actuator plate, each of the dummy channels is plane-symmetric with respect to a plane that passes through a center in the first direction of the dummy channels, the plane being perpendicular to the first direction, and the actuator plate includes communication portions configured to allow the dummy channels of the first channel row and the dummy channels of the second channel row to communicate with each other, the communication portions being formed between the first channel row and the second channel row, and the communication portions have a groove depth equal to a groove depth of the dummy channels. an actuator plate; a plurality of jet channels formed on the actuator plate, each of the jet channels extending lengthwise along a first direction and being filled with liquid; a plurality of dummy channels formed on the actuator plate, each of the dummy channels extending lengthwise along the first direction and not being filled with liquid; a jet hole plate laminated on the actuator plate and including a plurality of jet holes, each of the jet holes communicating with the corresponding one of the jet channels at a midway part in the first direction of the jet channel, wherein the actuator plate includes a first channel row including the jet channels and the dummy channels alternately arranged side by side in a second direction intersecting the first direction and a second channel row including the jet channels and the dummy channels alternately arranged side by side in the second direction, the first channel row and the second channel row being spaced apart from each other in the first direction, each of the jet channels is plane-symmetric with respect to a plane that passes through a center in the first direction of the jet channel, the plane being perpendicular to the first direction, the jet hole plate is configured to jet the liquid from the jet holes in a third direction perpendicular to the first direction and the second direction, the dummy channels of the first channel row and the dummy channels of the second channel row are open on respective end faces in the first direction of the actuator plate, each of the dummy channels is plane-symmetric with respect to a plane that passes through a center in the first direction of the dummy channels, the plane being perpendicular to the first direction, and the actuator plate includes communication portions configured to allow the dummy channels of the first channel row and the dummy channels of the second channel row to communicate with each other, the communication portions being formed between the first channel row and the second channel row, and the communication portions have a groove depth equal to a groove depth of the dummy channels.