To provide a lever float type drain trap which hardly allows a foreign matter to stick onto a normally open part and automatically removes the foreign matter sticking onto the normally open part.

The lever float type drain trap includes a valve seat 9 opening a valve opening communicating with a valve chamber 6 and an exit 2 and provided in a lower part of the valve chamber 6. A float 13 is housed inside the valve chamber 6. The float 13 surfacing/descending according to a liquid level inside the valve chamber 6 makes a valve body 16 leave/seat the valve seat 9 via a lever 12 to open/close the valve opening. A short pipe 21 into which the lever 12 is inserted is fixed inside the valve chamber 6. The lever 12 being brought into contact with a lower end 22 inside the short pipe prevents the valve body 16 from seating on the valve seat 9, thereby providing normal gaps 24 and 25 across the whole seal surface of the valve seat 9 between the valve seat 9 and the valve body 16.