A liquid ejection head fluidly connected to a storage chamber storing therein a liquid, the storage chamber having an outlet port and an inlet port , the liquid ejection head comprising: a plurality of discrete passages each having a nozzle , an inlet opening and an outlet opening ; a common channel in communication with the plurality of discrete passages , the common cannel being defined by two walls (22w1, 22w2) extending in a first direction which is a widthwise direction and facing with each other in a second direction which is a conveying direction perpendicular to the first direction, the common channel comprising: a common supply channel fluidly connected to the outlet port and to the inlet opening to introduce the liquid in the storage chamber to the plurality of discrete passages through the common supply channel ; and a common return channel fluidly connected to the outlet opening and to the inlet port to return the liquid in the plurality of discrete passages to the storage chamber , the common supply channel and the common return channel being positioned side by side in the second direction; and a protruding piece provided in each of the common supply channel and the common return channel and protruding from at least one of the walls (22w1, 22w2), characterized in that the protruding piece protrudes from each of the walls (22w1, 22w2) to connect the walls (22w1, 22w2) together, and the protruding piece includes an extending portion extending in a flowing direction of the liquid flowing through the common channel , the flowing direction being parallel to the first direction. a plurality of discrete passages each having a nozzle , an inlet opening and an outlet opening ; a common channel in communication with the plurality of discrete passages , the common cannel being defined by two walls (22w1, 22w2) extending in a first direction which is a widthwise direction and facing with each other in a second direction which is a conveying direction perpendicular to the first direction, the common channel comprising: a common supply channel fluidly connected to the outlet port and to the inlet opening to introduce the liquid in the storage chamber to the plurality of discrete passages through the common supply channel ; and a common return channel fluidly connected to the outlet opening and to the inlet port to return the liquid in the plurality of discrete passages to the storage chamber , the common supply channel and the common return channel being positioned side by side in the second direction; and a common supply channel fluidly connected to the outlet port and to the inlet opening to introduce the liquid in the storage chamber to the plurality of discrete passages through the common supply channel ; and a common return channel fluidly connected to the outlet opening and to the inlet port to return the liquid in the plurality of discrete passages to the storage chamber , the common supply channel and the common return channel being positioned side by side in the second direction; and a protruding piece provided in each of the common supply channel and the common return channel and protruding from at least one of the walls (22w1, 22w2), characterized in that the protruding piece protrudes from each of the walls (22w1, 22w2) to connect the walls (22w1, 22w2) together, and the protruding piece includes an extending portion extending in a flowing direction of the liquid flowing through the common channel , the flowing direction being parallel to the first direction. <EOS>