To provide an injection device for a combustion chamber of a liquid fuel rocket engine capable of reducing flow pressure loss, increasing stability in operation, and achieving uniform distribution of temperature and uniform distribution of output over a wide operation region.

This injection device is provided with an injection plate 10 arranged to face the combustion chamber 2, a first injection nozzle 32 for a first accelerator component, and a second injection nozzle 42 for a second accelerator component. Each of the first and second injection nozzles 32, 42 is provided with flow-in hole parts 33, 43 opened in the combustion chamber 2, and each of the first and second injection nozzles 32, 42 is provided with restriction hole parts 34, 44 extending coaxially with the flow-in hole parts 33, 43 in end parts on the opposite side to opening parts 31, 41 of the injection nozzles. Each of restriction hole parts 34, 44 has flow passage cross sectional area being equal to or smaller than flow passage cross sectional area of the flow-in hole parts 33, 43 corresponding to the restriction hole parts.