A multistage liquid storage-type condenser-evaporator comprising: a condensation passage which is configured to communicate in a vertical direction in which gas flows and is condensed; an evaporation passage which is configured to be divided into multiple stages in a vertical direction, through which liquid which is evaporated by exchanging heat with the gas flows; circulation liquid storage sections which are configured to be provided corresponding to the evaporation passage at each stage except a bottom stage, supply the liquid into the evaporation passage, store the liquid flowing out from the evaporation passage, and circulate the liquid in the evaporation passage at each stage; a communication passage which is configured to flow the liquid in the circulation liquid storage section at an upper stage into the circulation liquid storage section at lower stage; and a bottom communication passage which is configured to flow liquid in a bottom circulation liquid storage section into a bottom liquid storage section, the condensation passage and the evaporation passage are stacked to form a heat exchange section, the heat exchange section forms the heat exchanger core, and the circulation liquid storage section is formed on at least one side surface in a width direction of the heat exchanger core orthogonal to the stacking direction, corresponding to the number of stages of the evaporation passage, wherein the multistage liquid storage-type condenser-evaporator further comprises: the bottom liquid storage section which is configured to store the liquid supplied into the bottom evaporation passage without circulating, and a fluid collection section which is configured to collect the fluid which flows out from the bottom evaporation passage and discharge to the outside without returning into the bottom liquid storage section. a condensation passage which is configured to communicate in a vertical direction in which gas flows and is condensed; an evaporation passage which is configured to be divided into multiple stages in a vertical direction, through which liquid which is evaporated by exchanging heat with the gas flows; circulation liquid storage sections which are configured to be provided corresponding to the evaporation passage at each stage except a bottom stage, supply the liquid into the evaporation passage, store the liquid flowing out from the evaporation passage, and circulate the liquid in the evaporation passage at each stage; a communication passage which is configured to flow the liquid in the circulation liquid storage section at an upper stage into the circulation liquid storage section at lower stage; and a bottom communication passage which is configured to flow liquid in a bottom circulation liquid storage section into a bottom liquid storage section, the condensation passage and the evaporation passage are stacked to form a heat exchange section, the heat exchange section forms the heat exchanger core, and the circulation liquid storage section is formed on at least one side surface in a width direction of the heat exchanger core orthogonal to the stacking direction, corresponding to the number of stages of the evaporation passage, wherein the multistage liquid storage-type condenser-evaporator further comprises: the bottom liquid storage section which is configured to store the liquid supplied into the bottom evaporation passage without circulating, and a fluid collection section which is configured to collect the fluid which flows out from the bottom evaporation passage and discharge to the outside without returning into the bottom liquid storage section. the bottom liquid storage section which is configured to store the liquid supplied into the bottom evaporation passage without circulating, and a fluid collection section which is configured to collect the fluid which flows out from the bottom evaporation passage and discharge to the outside without returning into the bottom liquid storage section.