Infusion apparatus

An infusion apparatus comprising:

• an infusion set;
• and
• a controller,
• the infusion set including:
• a first flow path having a first connector, which is to be connected to a first container for storing a first liquid, at one end, and a downstream connector at the other end;
• a first open/close valve, a drip chamber, and a variable valve that are provided in this order on the first flow path from the first connector end toward the downstream connector end;
• a droplet sensor, a first liquid surface sensor, and a second liquid surface sensor that the drip chamber is provided with in this order from an upper end toward a lower end;
• an air discharge tube that is in communication with a gas storing portion in the drip chamber;
• an air discharge tube open/close valve that the air discharge tube is provided with;
• a second flow path having a second connector, which is to be connected to a second container for storing a second liquid, at one end;
• and
• a second open/close valve provided on the second flow path,
• wherein the second flow path is in communication with a portion of the first flow path between the first open/close valve and the drip chamber, and
• the controller is configured to control the first open/close valve, the variable valve, the second open/close valve, and the air discharge tube open/close valve based on signals from the droplet sensor, the first liquid surface sensor, and the second liquid surface sensor.