A scroll compressor having an injection function, the injection function including: suctioning a low-pressure working fluid; injecting an intermediate pressure working fluid into a compression chamber in a process of compressing the low-pressure working fluid; and discharging a high-pressure working fluid, the scroll compressor comprising: the compression chamber including a compression chamber partitioning member; an intermediate pressure chamber guiding the intermediate pressure working fluid before the injection to the compression chamber, wherein the intermediate pressure chamber and the compression chamber face each other with the compression chamber partitioning member interposed between the intermediate pressure chamber and the compression chamber, the intermediate pressure chamber includes: an intermediate pressure chamber inlet through which the intermediate pressure working fluid flows in; an injection port inlet of an injection port through which the intermediate pressure working fluid is injected into the compression chamber; and a liquid reservoir formed at a position below the intermediate pressure chamber inlet, the liquid reservoir including the compression chamber partitioning member, characterized in that the intermediate pressure chamber is formed of a fixed scroll, an intermediate pressure plate and an intermediate pressure cover constituting the intermediate pressure chamber partitioning member; and the intermediate pressure plate is provided with a check valve that prevents backflow of the working fluid from the compression chamber to the intermediate pressure chamber. the compression chamber including a compression chamber partitioning member; an intermediate pressure chamber guiding the intermediate pressure working fluid before the injection to the compression chamber, wherein the intermediate pressure chamber and the compression chamber face each other with the compression chamber partitioning member interposed between the intermediate pressure chamber and the compression chamber, the intermediate pressure chamber includes: an intermediate pressure chamber inlet through which the intermediate pressure working fluid flows in; an injection port inlet of an injection port through which the intermediate pressure working fluid is injected into the compression chamber; and a liquid reservoir formed at a position below the intermediate pressure chamber inlet, the liquid reservoir including the compression chamber partitioning member, characterized in that the intermediate pressure chamber is formed of a fixed scroll, an intermediate pressure plate and an intermediate pressure cover constituting the intermediate pressure chamber partitioning member; and the intermediate pressure plate is provided with a check valve that prevents backflow of the working fluid from the compression chamber to the intermediate pressure chamber. an intermediate pressure chamber inlet through which the intermediate pressure working fluid flows in; an injection port inlet of an injection port through which the intermediate pressure working fluid is injected into the compression chamber; and a liquid reservoir formed at a position below the intermediate pressure chamber inlet, the liquid reservoir including the compression chamber partitioning member, characterized in that the intermediate pressure chamber is formed of a fixed scroll, an intermediate pressure plate and an intermediate pressure cover constituting the intermediate pressure chamber partitioning member; and the intermediate pressure plate is provided with a check valve that prevents backflow of the working fluid from the compression chamber to the intermediate pressure chamber.