Developing apparatus

A developing apparatus, comprising:

• a body;
• a buffer plate fixedly installed on the body and including a gas flow groove through which a gas is flowable;
• a vacuum plate fixedly installed on an upper surface of the buffer plate and having a gas supply hole in fluid communication with the gas flow groove, the vacuum plate including a plurality of vacuum holes for holding a substrate;
• and
• a slit block fixedly installed on an edge of the vacuum plate, the slit block and the vacuum plate together forming a buffer space and an inclined first flow path for gas supplied through the gas supply hole,
• wherein:
• a contact area between the substrate and the vacuum plate is equal to 90% or more of an area of the substrate when the substrate is held by the vacuum plate,
• an edge of the substrate protrudes outwardly relative to the edge of the vacuum plate,
• the buffer space and the inclined first flow path are in fluid communication with the buffer space such that the gas is introducible into the buffer space from the gas supply hole,
• the slit block together with the edge of the substrate held on the vacuum plate forms a second flow path in fluid communication with to the inclined first flow path, and
• a cross-sectional area of the second flow path is equal to 70% or less of a cross-sectional area of the gas supply hole.