Apparatus for treating substrate

An apparatus for treating a substrate using a plurality of treatment solutions, the apparatus comprising:

• a supporting member receiving the substrate thereon and rotating the substrate;
• a treatment liquid supplying member supplying the treatment solutions to the substrate placed on the supporting member;
• and
• a treatment liquid collecting member forming a space therein for placing the supporting member and including passages for separately collecting the treatment solutions supplied from the treatment liquid supplying member,
• wherein the treatment liquid collecting member comprises:
• an inner base including a bottom wall, an inner wall, and an outer wall that form a space for receiving the treatment solution, the inner base being formed with a drain hole for discharging the treatment solution;
• an outer base surrounding the inner base and including a bottom wall and an outer wall that form a space for receiving the treatment solution, the outer base being formed with a drain hole for discharging the treatment solution;
• an inner guide disposed on the outer wall of the inner base and providing a passage to introduce the treatment solution into the space formed in the inner base;
• and
• an outer guide disposed on the outer wall of the outer base and providing a passage to introduce the treatment solution into the space formed in the outer base,
• wherein the inner guide is disposed on the outer wall of the inner base by a groove-protrusion engagement structure formed on an upper end of the outer wall of the inner base and a lower end of the inner guide, and the outer guide is disposed on the outer wall of the inner base by a groove-protrusion engagement structure formed on an upper end of the outer wall of the outer base and a lower end of the outer guide.