Member for semiconductor manufacturing apparatus

A member for semiconductor manufacturing apparatus comprising:

• a ceramic plate having an object support surface capable of supporting an object on its upper surface;
• a plug placement hole penetrating the ceramic plate in an up-down direction;
• and
• a plug arranged in the plug placement hole and having a gas flow path formed so as to extend from an inlet provided in a lower surface of a plug body to an outlet provided in an upper surface thereof,
• wherein, when the plug is viewed in longitudinal section, a length in an up-down direction of the gas flow path is d1 [mm], a length in an up-down direction of the plug body between the gas flow paths is d2 [mm], a relative permittivity of the plug body is εr, and a number of the gas flow paths arranged in the up-down direction in the longitudinal section of the plug is x [pieces], the member for semiconductor manufacturing apparatus satisfying:
• F
• =
• ε
• ⁢
• r
• *
• d
• ⁢
• 1
• /
• {
• x
• *
• (
• ε
• ⁢
• r
• *
• d
• ⁢
• 1
• +
• d
• ⁢
• 2
• )
• }
• ≤
• 0.25
• .