Under-sink water purifier

A modular under-sink water purifier, comprising:

• a main module provided in a sink;
• and
• a faucet disposed outside the sink, wherein the main module comprises:
• a main module housing having a first coupling part and a second coupling part provided, respectively, at one side portion and the other side portion thereof so that a portion of a sub-module, which can be detachably coupled to the main module, can be selectively coupled thereto;
• filters provided in the main module housing, and filtering raw water so as to produce purified water ;
• and
• a first water discharge member and a second water discharge member provided, respectively, at one side of the first coupling part and one side of the second coupling part so that the purified water produced by means of the filters can be discharged to the outside of the main module housing, and
• wherein the faucet comprises:
• a faucet housing;
• and
• a third water discharge member provided at the faucet housing so that the purified water supplied from the filters can be discharged to the outside.