An injection device comprising: a device main body partitioned into a fuel manifold and an oxidant manifold; and a plurality of injectors (22,23,24) arranged at predetermined intervals in the device main body and configured to inject fuel and oxidant, when in use, into a combustion chamber, wherein the plurality of injectors (22,23,24) each includes an oxidant channel (43a,43b) including a proximal end portion communicating with the oxidant manifold and a distal end portion communicating with the combustion chamber, a restrictor (45a,45b,45c,45d) provided on the proximal end portion of the oxidant channel (43a,43b), and a fuel channel (47a,47b) including a proximal end portion communicating with the fuel manifold and a distal end portion communicating with the combustion chamber, wherein the restrictors (45a,45b,45c,45d) in the plurality of injectors (22,23,24) have different shapes, wherein shapes of the restrictors (45a,45b,45c,45d) in the plurality of injectors (22,23,24) are set different in accordance with a pressure oscillation mode occurring in the combustion chamber in which the injection device is to be used, and wherein the shapes of the restrictors (45a,45b,45c,45d) are set to amplify pressure oscillation of a preset certain frequency, and the combustion chamber, in which the injection device is to be used, communicates with a resonator configured to attenuate the pressure oscillation of the certain frequency. a device main body partitioned into a fuel manifold and an oxidant manifold; and a plurality of injectors (22,23,24) arranged at predetermined intervals in the device main body and configured to inject fuel and oxidant, when in use, into a combustion chamber, wherein the plurality of injectors (22,23,24) each includes an oxidant channel (43a,43b) including a proximal end portion communicating with the oxidant manifold and a distal end portion communicating with the combustion chamber, a restrictor (45a,45b,45c,45d) provided on the proximal end portion of the oxidant channel (43a,43b), and a fuel channel (47a,47b) including a proximal end portion communicating with the fuel manifold and a distal end portion communicating with the combustion chamber, an oxidant channel (43a,43b) including a proximal end portion communicating with the oxidant manifold and a distal end portion communicating with the combustion chamber, a restrictor (45a,45b,45c,45d) provided on the proximal end portion of the oxidant channel (43a,43b), and a fuel channel (47a,47b) including a proximal end portion communicating with the fuel manifold and a distal end portion communicating with the combustion chamber, wherein the restrictors (45a,45b,45c,45d) in the plurality of injectors (22,23,24) have different shapes, wherein shapes of the restrictors (45a,45b,45c,45d) in the plurality of injectors (22,23,24) are set different in accordance with a pressure oscillation mode occurring in the combustion chamber in which the injection device is to be used, and wherein the shapes of the restrictors (45a,45b,45c,45d) are set to amplify pressure oscillation of a preset certain frequency, and the combustion chamber, in which the injection device is to be used, communicates with a resonator configured to attenuate the pressure oscillation of the certain frequency.