A binary cycle power generation system includes a working fluid circulation line, an evaporator, an expander, an energy recovery apparatus, a condenser, and a pump. The pump includes a casing, a rotary shaft, and impellers. The casing is hollow and has an end wall at an end in a longitudinal direction. The rotary shaft has an axis extending in the longitudinal direction of the casing, is supported on the end wall, has at least a part that is in the casing, and rotates owing to a torque. The impellers are attached to the rotary shaft one after another in the longitudinal direction. The pump is arranged in such a way that the axis of the rotary shaft intersects a vertical direction.