A syringe barrel (15, 15a to 15c) comprising: a barrel body including a nozzle portion at a distal end thereof; and a cap (14, 14a to 14c) removably mounted to the nozzle portion and configured to seal a distal end opening of the nozzle portion, wherein the cap (14, 14a to 14c) comprises: an inner cap formed of an elastic material and configured to come in liquid tight close contact with the nozzle portion in a mounted state in which the cap (14, 14a to 14c) is mounted to the nozzle portion, and a cylindrical outer cap (36, 36a to 36c) formed of a material having higher hardness than the inner cap and fixed around the inner cap, wherein the inner cap comprises: a base portion; and a cylindrical wall extending from the base portion in a proximal direction and surrounding the nozzle portion, characterized in that the cylindrical wall is configured to be sandwiched in a compressed state between an outer peripheral surface of the nozzle portion and an inner peripheral surface of the outer cap (36, 36a to 36c) in a state in which the base portion is in close contact with a distal end surface of the nozzle portion and in a state in which the base portion is apart from the distal end surface of the nozzle portion by a predetermined distance, such that the cylindrical wall is in liquid tight close contact over a full circumference with the outer peripheral surface of the nozzle portion, wherein an axial length of a compressed portion, which is a portion of the cylindrical wall portion compressed between the nozzle portion and the outer cap (36, 36a to 36c) in a state in which the base portion is in close contact with the distal end surface of the nozzle portion, is 0.5 mm or more, and wherein the axial length of the compressed portion is shorter than an axial length of the cylindrical wall. a barrel body including a nozzle portion at a distal end thereof; and a cap (14, 14a to 14c) removably mounted to the nozzle portion and configured to seal a distal end opening of the nozzle portion, wherein the cap (14, 14a to 14c) comprises: an inner cap formed of an elastic material and configured to come in liquid tight close contact with the nozzle portion in a mounted state in which the cap (14, 14a to 14c) is mounted to the nozzle portion, and a cylindrical outer cap (36, 36a to 36c) formed of a material having higher hardness than the inner cap and fixed around the inner cap, an inner cap formed of an elastic material and configured to come in liquid tight close contact with the nozzle portion in a mounted state in which the cap (14, 14a to 14c) is mounted to the nozzle portion, and a cylindrical outer cap (36, 36a to 36c) formed of a material having higher hardness than the inner cap and fixed around the inner cap, wherein the inner cap comprises: a base portion; and a cylindrical wall extending from the base portion in a proximal direction and surrounding the nozzle portion, a base portion; and a cylindrical wall extending from the base portion in a proximal direction and surrounding the nozzle portion, characterized in that the cylindrical wall is configured to be sandwiched in a compressed state between an outer peripheral surface of the nozzle portion and an inner peripheral surface of the outer cap (36, 36a to 36c) in a state in which the base portion is in close contact with a distal end surface of the nozzle portion and in a state in which the base portion is apart from the distal end surface of the nozzle portion by a predetermined distance, such that the cylindrical wall is in liquid tight close contact over a full circumference with the outer peripheral surface of the nozzle portion, wherein an axial length of a compressed portion, which is a portion of the cylindrical wall portion compressed between the nozzle portion and the outer cap (36, 36a to 36c) in a state in which the base portion is in close contact with the distal end surface of the nozzle portion, is 0.5 mm or more, and wherein the axial length of the compressed portion is shorter than an axial length of the cylindrical wall.