Gas supply system and semiconductor manufacturing apparatus

A gas supply system comprising:

• a gas box housing in which a precursor container accommodating a gas precursor is disposed;
• at least one pipe passing through a through-hole in the gas box housing, through which a fluid flowing into the gas box housing from outside flows, or a fluid flowing out of the gas box housing to the outside flows;
• and
• a block member installed in the through-hole and including a pipe surrounding portion configured to integrally surround an inner pipe portion that is a portion of the pipe inside the gas box housing and an outer pipe portion that is a portion of the pipe outside the gas box housing,
• wherein, in a state where the pipe surrounding portion is inserted into a gap between an inner peripheral surface of the through-hole and an outer peripheral surface of the pipe passing through the through-hole, the block member is fixed to the gas box housing to block the gap.