Flow controller

A flow controller comprising,

• a base in which an inlet port and an outlet port of a gas are prepared on a surface of said base and a passage communicating said inlet port and said outlet port with each other is prepared inside said base,
• a flow sensor which measures a flow rate of said gas flowing through said passage, and
• at least two flow control valves which have the same specification and control the flow rate of said gas flowing through said passage,
• wherein:
• said passage comprises,
• an inlet passage that is a space which communicates with said inlet port,
• a branching part that is a space which communicates with said inlet passage and branches a flow of said gas,
• branch passages that are at least two spaces which communicate with said branching part in parallel,
• a joining part that is a space which communicates with said branch passages and makes said flows of said gas join together, and
• an outlet passage that is a space which makes said joining part communicate with said outlet port, and
• said flow sensor is configured so as to detect a total flow rate of said gas which flows through said passage, and
• at least one of said flow control valves is interposed in each of said branch passages.