A device control system including a wearable device and a server. The wearable device includes a device that ejects a fragrance material, a biological sensor, and a computer. The computer transmits biological data to the server, receives a first control signal, and causes the device to eject a fragrance material upon receipt of the first control signal. The server includes a computer. The computer receives the biological data, estimates user's emotion from the received biological data, and in a case where it is determined that the user has positive emotion by using a result of the estimation, (i) transmits the first control signal to the wearable device and (ii) transmits, to an aroma device, a second control signal for causing the aroma device to eject a fragrance material at a predetermined timing.