A heat-medium discharge device and a heat-medium discharge method capable of discharging a heat medium from a solar heat collection device in short time without installing a tank at a position lower than the solar heat collection device are provided. A heat-medium discharge device includes: a vent portion (15) which is provided at a highest position of a heat medium channel (2); compressed air supply means (12) which supplies compressed air to the heat medium channel (2) when a heat medium is discharged; a pipe (5) which is connected to the heat medium channel (2); and a tank (6) which is connected to the pipe (5) and stores the heat medium fed from the heat medium channel (2) by the compressed air and flowing through the pipe (5). Accordingly, when the vent portion (15) is opened so that air is introduced into the heat medium channel (2) and compressed air is supplied from the compressed air supply means (12) during the heat medium discharge operation, the heat medium which is fed from the heat medium chann
