To provide a float type steam trap that can reliably prevent erosion in an exit passage.

A trap casing comprising cap member 2 and a body 1 having an entrance 5 and an exit 7 includes a trap chamber 4 communicating the entrance 5 and an exit passage 6 communicating the exit 7 formed therein. A cylindrical valve seat 3 having a drain valve hole 10 that communicates the trap chamber 4 to the exit passage 6 is attached to a lower part of the trap chamber 4. A plurality of small holes 8 is disposed in the cylindrical valve seat 3 to communicate with the exit passage 6. The center axis of the small hole 8 and the center axis of the exit passage 6 are arranged approximately parallel to each other. A float 13 which opens and closes an end of the drain valve hole 10 close to the trap chamber 4, in accordance with a liquid level in the trap chamber 4, is housed in the trap chamber 4. Steam condensate discharged from the plurality of small holes 8 is less likely to directly collide with an inner peripheral wall face of the exit passage 6 inclining toward the exit 7, and thereby, erosion on the inner peripheral wall face of the exit passage 6 can be prevented.