A medical system includes an endoscope which is a first medical instrument, a gas supply apparatus which is a second medical instrument that supplies a gas to an insertion site at which an insertion portion of the endoscope is inserted, a biological information acquiring apparatus which is a biological information detection section that detects a blood flow rate at the insertion site as a biological information detected value, a manipulation information acquiring apparatus which is a manipulation information detection section that contacts the insertion portion of the endoscope and is combined with a roller that rotates as the insertion portion moves forward or backward to detect an amount of rotation of the roller as manipulation information, and a system control apparatus provided with a control section that outputs an instruction signal for changing an amount of gas supply to the gas supply apparatus according to the detected value detected by the biological information acquiring apparatus and the manipulation information detected by the manipulation information acquiring apparatus.
