A human-collaborative robot system includes a detection unit that directly or indirectly detects a physical quantity which is changed in response to contact force applied to a robot when the robot comes in contact with an external environment, and a stop command unit that compares the physical quantity detected by the detection unit with a first threshold value and a second threshold value greater than the first threshold value, stops the robot according to a predetermined stop method when the physical quantity is equal to or greater than the first threshold value and is smaller than the second threshold value, and stops the robot in a shorter period of time as compared with the predetermined stop method when the physical quantity is equal to or greater than the second threshold value.