To provide a steam trap for short face-to-face dimension for reducing the size of an inlet and an outlet.

This steam trap for short face-to-face dimension includes a connection part 1 and a steam trap 2. The connection part 1 includes the inlet 3 and the outlet 4 formed on the same axis, an inlet path 5 connecting the inlet 3 with a valve chamber in the steam trap 2, and a communication path 6 communicating with the outlet 4. A flange-shaped wafer type flangeless part 7 is formed on the outer periphery of the inlet 3, and a flange-shaped wafer type flangeless part 8 is formed on the outer periphery of the outlet 4. A valve member is disposed in the valve chamber inside the steam trap 2 to discharge, to the outlet 4, only the condensed water contained in the mixed fluid of the condensed water and steam flowing from the inlet 3 thereto, and to prevent the steam from being discharged. The wafer type flangeless part is employed between the inlet 3 and the outlet 4 in the connection part 1, thereby reducing the side of the inlet 3 and the outlet 4, to form the steam trap for short face-to-face dimension.