A redox flow battery (1A, 1B) comprising: a stack group including a plurality of cell stacks (10, 101, 102) that are arranged side by side in a horizontal direction; a heat exchanger that is disposed above the stack group and that cools an electrolyte supplied to each of the cell stacks (10, 101, 102); and a container that collectively houses the stack group, the heat exchanger, a tank that stores the electrolyte, and a pipe (16, 164, 165) which is connected to each of the cell stacks (10, 101, 102) and the tank and through which the electrolyte flows, wherein the container includes a cell chamber that houses the stack group, the heat exchanger, and the pipe (16, 164, 165) and a tank chamber that houses the tank, the cell chamber and the tank chamber being arranged side by side in a longitudinal direction of the container, characterized in that: a length of the tank chamber is longer than a length of the cell chamber, a center of the container in the longitudinal direction and a height direction is denoted by P, a center of the container in the longitudinal direction and a width direction is denoted by Q, a length of the container is denoted by L, a width of the container is denoted by W, and a center of gravity of the container is denoted by G in a state in which the tank is empty without storing the electrolyte, and a distance x from the center P to the center of gravity G satisfies x ≤ (1/3) × L on a longitudinal section of the container in a state in which the stack group, the heat exchanger, the tank, and the pipe (16, 164, 165) are housed, and a distance y from the center Q to the center of gravity G satisfies y ≤ (1/20) × W on a horizontal section of the container. a stack group including a plurality of cell stacks (10, 101, 102) that are arranged side by side in a horizontal direction; a heat exchanger that is disposed above the stack group and that cools an electrolyte supplied to each of the cell stacks (10, 101, 102); and a container that collectively houses the stack group, the heat exchanger, a tank that stores the electrolyte, and a pipe (16, 164, 165) which is connected to each of the cell stacks (10, 101, 102) and the tank and through which the electrolyte flows, wherein the container includes a cell chamber that houses the stack group, the heat exchanger, and the pipe (16, 164, 165) and a tank chamber that houses the tank, the cell chamber and the tank chamber being arranged side by side in a longitudinal direction of the container, characterized in that: a length of the tank chamber is longer than a length of the cell chamber, a center of the container in the longitudinal direction and a height direction is denoted by P, a center of the container in the longitudinal direction and a width direction is denoted by Q, a length of the container is denoted by L, a width of the container is denoted by W, and a center of gravity of the container is denoted by G in a state in which the tank is empty without storing the electrolyte, and a length of the tank chamber is longer than a length of the cell chamber, a center of the container in the longitudinal direction and a height direction is denoted by P, a center of the container in the longitudinal direction and a width direction is denoted by Q, a length of the container is denoted by L, a width of the container is denoted by W, and a center of gravity of the container is denoted by G in a state in which the tank is empty without storing the electrolyte, and