Dishwasher

A dishwasher comprising:

• a sump housing for holding washing water;
• a washing water pumping unit for pumping the washing water;
• a drain chamber for receiving the washing water pumped by the washing water pumping unit and for depositing particles contained in the washing water by gravity of the particles;
• a soil chamber, positioned above the drain chamber, for receiving the washing water after the washing water has passed through the drain chamber;
• a guide assembly for guiding the washing water pumped by the washing water pumping unit to be provided to the soil chamber via the drain chamber;
• and
• a sump cover covered on an upper surface of the sump housing for filtering the washing water overflowed from the soil chamber;
• wherein the guide assembly includes:
• a sampling flow passage for guiding a portion of the pumped washing water to the drain chamber, and
• a plurality of main flow passages for guiding the washing water not provided to the sampling flow passage to at least one spray arm.