Member for semiconductor manufacturing apparatus

A member for semiconductor manufacturing apparatus, comprising:

• a ceramic plate having a wafer placement surface at an upper surface and incorporating an electrode;
• a conductive base plate provided on a lower surface side of the ceramic plate;
• a gas common passage provided inside the base plate;
• gas outlet passages provided for the gas common passage to reach the wafer placement surface from the gas common passage;
• at least one gas inlet passage provided for the gas common passage and provided so as to communicate with the gas common passage from a lower surface of the base plate, the number of the at least one gas inlet passage being less than the number of the gas outlet passages;
• and
• an insulating sleeve disposed in a base plate through-hole which penetrates the base plate in up-down direction,
• wherein the insulating sleeve has a first communication hole that constitutes part of the gas common passage, and a second communication hole that is provided to reach an upper surface of the insulating sleeve from the first communication hole, and constitutes part of the gas outlet passages, and
• wherein the at least one gas inlet passage is connected to at least one end of the gas common passage, and
• wherein the gas common passage is c-shaped or spiral shaped in plan view.